Instead of the factor() function which usually applies after defining a vector there’s the gl() base function to do this in one step, eg

freq <- c(204,6,1,211,13,5,357,44,38,92,34,49)
row <- gl(4,3,length=12)
col <- gl(3,1,length=12)
> col
[1] 1 2 3 1 2 3 1 2 3 1 2 3
Levels: 1 2 3
tt <- data.frame(freq,row,col)
> xtabs(tt)
col
row   1   2   3
 1 204   6   1
 2 211  13   5
 3 357  44  38
 4  92  34  49