Does this help?
a <- c(1,1,1,1,1,2,2,2,2,2)
b <- c(4,5,6,5,4,7,8,9,8,7)
c <- c("a","b","c","d","a","b","b","a","d","d")
A <- cbind(a,b,c)
test <- ftable(a,b,c)
test.df <- data.frame(test)
test.df[test.df$Freq != 0, ]
Doesn't quite give the layout you seem to want, but effectively removes the zeros.
Mikkel