> xtabs(~gear+am,mtcars)
    am
gear  0  1
   3 15  0
   4  4  8
   5  0  5
>

> as.data.frame.matrix(xtabs(~gear+am,mtcars))
   0 1
3 15 0
4  4 8
5  0 5
>

library(tidyverse)
data.frame(xtabs(~gear + am, mtcars)) %>%
    mutate(am = paste0("am", am)) %>%
    spread(am, Freq)

  gear am0 am1
1    3  15   0
2    4   4   8
3    5   0   5

r.t <- xtabs(~ gear + am, mtcars)
r.d <- as.data.frame.matrix(r)
rownames(r.d) <- paste0(names(dimnames(r.t))[1], dimnames(r.t)[[1]])
colnames(r.d) <- paste0(names(dimnames(r.t))[2], dimnames(r.t)[[2]])
r.d

#       am0 am1
# gear3  15   0
# gear4   4   8
# gear5   0   5