I created my file for html manually and reading it in as an HTML file.

myurl <- "https://raw.githubusercontent.com/BanuB/Week7Assignment/master/Books2.html"
html<-tbl_df(as.data.frame(read_html(myurl) %>% html_table(header = NA, trim=TRUE, fill=TRUE)))
html %>% kable() %>% kable_styling() %>% scroll_box(width = "910px")
SNO Book Subject Authors Cost ISBN.10 PrintLength Format.Type Publisher
1 SQL Server 2016 Developer’s Guide: Build efficient database applications for your organization with SQL Server 2016 Database Database Dejan Sarka (Author), Milos Radivojevic (Author), William Durkin  (Author) 37.67 1786465345 616 Paperback Packt Publishing (March 22, 2017)
2 SQL Server 2016 Developer’s Guide: Build efficient database applications for your organization with SQL Server 2016 Database Database Dejan Sarka (Author), Milos Radivojevic (Author), William Durkin  (Author) 55.99 1786465345 616 Hardcover Packt Publishing (March 22, 2017)
3 North and South (Wordsworth Classics) 2nd Revised ed. Edition Classic Literature Dejan Sarka (Author), Milos Radivojevic (Author), William Durkin  (Author) 55.99 1786465345 616 Paperback Packt Publishing (March 22, 2017)
4 Fashion in Detail: World Dress (paperback) Fashion Rosemary Crill, Jennifer Wearden and Verity Wilson 25.08 1851775684 224 Paperback V & A Publishing; 1st edition (April 1, 2009)
5 Pride and Prejudice Classic Literature Jane Auston 9.45 1503290565 226 Paperback CreateSpace Independent Publishing Platform (November 6, 2018)

Created and read in an XML file

myXML <- getURL("https://raw.githubusercontent.com/BanuB/Week7Assignment/master/BooksXML2.xml")
xmlData<-xmlToDataFrame(myXML)
xmlData %>% kable() %>% kable_styling() %>% scroll_box(width = "910px")
SNO BookTitle Subject Authors Cost ISBN-10 PrintLength FormatType Publisher
1 SQL Server 2016 Developer’s Guide: Build efficient database applications for your organization with SQL Server 2016 Database Dejan Sarka (Author), Milos Radivojevic (Author), William Durkin  (Author) 37.7 1786465345 616 Paperback Packt Publishing (March 22, 2017)
2 SQL Server 2016 Developer’s Guide: Build efficient database applications for your organization with SQL Server 2016 Database Dejan Sarka (Author), Milos Radivojevic (Author), William Durkin  (Author) 56 1786465345 616 Hardcover Packt Publishing (March 22, 2017)
3 North and South (Wordsworth Classics) 2nd Revised ed. Edition Classic Literature Elizabeth Gaskell 3.95 1853260932 448 Paperback Wordsworth Editions; 2nd Revised ed. edition (April 1, 1998)
4 Fashion in Detail: World Dress (paperback) Fashion Rosemary Crill, Jennifer Wearden and Verity Wilson 25.1 1851775684 616 Paperback V & A Publishing; 1st edition (April 1, 2009)
5 Pride and Prejudice Classic Literature Jane Auston 9.45 1503290565 226 Paperback CreateSpace Independent Publishing Platform (November 6, 2018)

Reading in a json file

myjson<-fromJSON(content = "https://raw.githubusercontent.com/BanuB/Week7Assignment/master/Booksjson.JSON")
myjsontb<-do.call("cbind", lapply(myjson[[1]], data.frame, stringsAsFactors = FALSE))
s <- t(myjsontb)
s %>% kable() %>% kable_styling() %>% scroll_box(width = "910px")
SNO BookTitle Subject Authors Cost ISBN-10 PrintLength FormatType Publisher
X..i.. 1 SQL Server 2016 Developer’s Guide: Build efficient database applications for your organization with SQL Server 2016 Database Dejan Sarka (Author), Milos Radivojevic (Author), William Durkin  (Author) 37.7 1786465345 616 Paperback Packt Publishing (March 22, 2017)
X..i.. 2 SQL Server 2016 Developer’s Guide: Build efficient database applications for your organization with SQL Server 2016 Database Dejan Sarka (Author), Milos Radivojevic (Author), William Durkin  (Author) 56 1786465345 616 Paperback Packt Publishing (March 22, 2017)
X..i.. 3 North and South (Wordsworth Classics) 2nd Revised ed. Edition Classic Literature Elizabeth Gaskell 3.95 1853260932 448 Paperback Wordsworth Editions; 2nd Revised ed. edition (April 1, 1998)
X..i.. 4 Fashion in Detail: World Dress (paperback) Fashion Rosemary Crill, Jennifer Wearden and Verity Wilson 25.1 1851775684 616 Paperback V &amp; A Publishing; 1st edition (April 1, 2009)
X..i.. 5 Pride and Prejudice Classic Literature Jane Auston 9.45 1503290565 226 Paperback CreateSpace Independent Publishing Platform (November 6, 2018)
str(xmlData)
## 'data.frame':    5 obs. of  9 variables:
##  $ SNO        : Factor w/ 5 levels "1","2","3","4",..: 1 2 3 4 5
##  $ BookTitle  : Factor w/ 4 levels "Fashion in Detail: World Dress (paperback)",..: 4 4 2 1 3
##  $ Subject    : Factor w/ 3 levels "Classic Literature",..: 2 2 1 3 1
##  $ Authors    : Factor w/ 4 levels "Dejan Sarka (Author), Milos Radivojevic (Author), William Durkin  (Author)",..: 1 1 2 4 3
##  $ Cost       : Factor w/ 5 levels "25.1","3.95",..: 3 4 2 1 5
##  $ ISBN-10    : Factor w/ 4 levels " 1503290565",..: 2 2 4 3 1
##  $ PrintLength: Factor w/ 3 levels "226","448","616": 3 3 2 3 1
##  $ FormatType : Factor w/ 2 levels "Hardcover","Paperback": 2 1 2 2 2
##  $ Publisher  : Factor w/ 4 levels "CreateSpace Independent Publishing Platform (November 6, 2018)",..: 2 2 4 3 1
str(html)
## Classes 'tbl_df', 'tbl' and 'data.frame':    5 obs. of  9 variables:
##  $ SNO        : int  1 2 3 4 5
##  $ Book       : chr  "SQL Server 2016 Developer's Guide: Build efficient database applications for your organization with SQL Server 2016 Database" "SQL Server 2016 Developer's Guide: Build efficient database applications for your organization with SQL Server 2016 Database" "North and South (Wordsworth Classics) 2nd Revised ed. Edition" "Fashion in Detail: World Dress (paperback)" ...
##  $ Subject    : chr  "Database" "Database" "Classic Literature" "Fashion" ...
##  $ Authors    : chr  "Dejan Sarka (Author), Milos Radivojevic (Author), William Durkin  (Author)" "Dejan Sarka (Author), Milos Radivojevic (Author), William Durkin  (Author)" "Dejan Sarka (Author), Milos Radivojevic (Author), William Durkin  (Author)" "Rosemary Crill, Jennifer Wearden and Verity Wilson" ...
##  $ Cost       : num  37.67 55.99 55.99 25.08 9.45
##  $ ISBN.10    : int  1786465345 1786465345 1786465345 1851775684 1503290565
##  $ PrintLength: int  616 616 616 224 226
##  $ Format.Type: chr  "Paperback" "Hardcover" "Paperback" "Paperback" ...
##  $ Publisher  : chr  "Packt Publishing (March 22, 2017)" "Packt Publishing (March 22, 2017)" "Packt Publishing (March 22, 2017)" "V & A Publishing; 1st edition (April 1, 2009)" ...
str(s)
##  chr [1:5, 1:9] "1" "2" "3" "4" "5" ...
##  - attr(*, "dimnames")=List of 2
##   ..$ : chr [1:5] "X..i.." "X..i.." "X..i.." "X..i.." ...
##   ..$ : chr [1:9] "SNO" "BookTitle" "Subject" "Authors" ...

For the HTML file creation, I manually created the file, For XML, manually created a file as well. For XML the & in the attribute value caused an error so I had to resubmit the equivalent & . JSON file was created but I had to use like lapply and transpose steps to show the information in a dataframe format. The HTML and XML seem to similar in structure. For JSON, we were reading in a list and then I perform cbind and then transpose to get it in the similar structure as the HTML and XML files.