Leave only those rows in matrices which have equal elements at certain column

Question

Let me show an example. Consider we have 3 tables (focus on columns N):

   Table 1         Table 2        Table 3
-------------   -------------   -------------
           


        

Answer 1

Once you find the "common denominator" (here Table1), you could do like this:

Table2 <- Table2[Table2$N %in% Table1$N,]
Table3 <- Table3[Table3$N %in% Table1$N,]