\[ \begin{aligned} \begin{array}[t]{} % Wed Feb 12 18:46:21 2014 \begin{array}[t]{rrrr} \hline & 1 & 2 & 3 \\ \hline 1 & 1 & 4 & 7 \\ 2 & 2 & 5 & 8 \\ 3 & 3 & 6 & 9 \\ \hline \end{array} & % Wed Feb 12 18:46:21 2014 \begin{array}[t]{rrrrr} \hline & 1 & 2 & 3 & 4 \\ \hline 1 & 1 & 5 & 9 & 13 \\ 2 & 2 & 6 & 10 & 14 \\ 3 & 3 & 7 & 11 & 15 \\ 4 & 4 & 8 & 12 & 16 \\ \hline \end{array} & % Wed Feb 12 18:46:21 2014 \begin{array}[t]{rrrrrr} \hline & 1 & 2 & 3 & 4 & 5 \\ \hline 1 & 1 & 6 & 11 & 16 & 21 \\ 2 & 2 & 7 & 12 & 17 & 22 \\ 3 & 3 & 8 & 13 & 18 & 23 \\ 4 & 4 & 9 & 14 & 19 & 24 \\ 5 & 5 & 10 & 15 & 20 & 25 \\ \hline \end{array} \end{array} \end{aligned} \]
$$
library(xtable)
tab2arr <- function(tbl) {
tbl <- lapply( tbl, xtable )
tbl <- lapply( tbl, toLatex )
tbl <- lapply( tbl, sub, pattern='.*table.*', replacement='')
tbl <- lapply( tbl, sub, pattern='.*centering.*', replacement='')
tbl <- lapply( tbl, sub, pattern='begin\\{tabular\\}', replacement='begin\\{array\\}[t]')
tbl <- lapply( tbl, sub, pattern='(tabular\\})', replacement='array}')
tbl
}
tbl <- list( matrix(1:9,3,3), matrix(1:16,4,4), matrix(1:25,5,5) )
tbl <- tab2arr(tbl)
writeLines( text=c( '\\begin{aligned}',
'\\begin{array}[t]{}',
tbl[[1]],
'&',
tbl[[2]],
'&',
tbl[[3]],
'\\end{array}',
'\\end{aligned}') )
$$