MHmakeRandomString <- function(n, length) {
   randomString <- c(1:n)
   for (i in 1:n) {
     randomString[i] <- paste(sample(c(0:9, letters, LETTERS), length, replace=TRUE),
                              collapse="")}
   return(randomString)
}
set.seed(4)
word_vector <- MHmakeRandomString(n=40, length=5)
word_sep <- paste(word_vector, collapse=", ")
f <- gsub("((?:[^,]*,){10}) ", "\\1\n", word_sep)
cat(f, collapse="\n")