library(tidyverse)

agents <- tibble::tribble(
                 ~name,                                 ~alias,             ~drink,
     "Sterling Archer", "Randy Magnum, Randy Randerson, Rando", "Glengoolie Black",
          "Pam Poovey",                 "Shiroi Kabocha, Ruth",   "Green Russians",
         "Cheryl Tunt",              "Carol, Carina, Cherlene",             "Glue",
        "Cyril Figgis",          "Chet Manley, Odie McCracken",     "Old Buncombe"
     )

agents

## # A tibble: 4 x 3
##   name            alias                                drink           
##   <chr>           <chr>                                <chr>           
## 1 Sterling Archer Randy Magnum, Randy Randerson, Rando Glengoolie Black
## 2 Pam Poovey      Shiroi Kabocha, Ruth                 Green Russians  
## 3 Cheryl Tunt     Carol, Carina, Cherlene              Glue            
## 4 Cyril Figgis    Chet Manley, Odie McCracken          Old Buncombe

agents %>%
  tidyr::separate_rows("alias", sep = ", ")

## # A tibble: 10 x 3
##    name            alias           drink           
##    <chr>           <chr>           <chr>           
##  1 Sterling Archer Randy Magnum    Glengoolie Black
##  2 Sterling Archer Randy Randerson Glengoolie Black
##  3 Sterling Archer Rando           Glengoolie Black
##  4 Pam Poovey      Shiroi Kabocha  Green Russians  
##  5 Pam Poovey      Ruth            Green Russians  
##  6 Cheryl Tunt     Carol           Glue            
##  7 Cheryl Tunt     Carina          Glue            
##  8 Cheryl Tunt     Cherlene        Glue            
##  9 Cyril Figgis    Chet Manley     Old Buncombe    
## 10 Cyril Figgis    Odie McCracken  Old Buncombe