Group and subgroup make more sense than row and col.

[mbcann01]

Row and column make sense for a contingency table, but not so much for a frequency table (click here to see the difference).

For a frequency table, we should use group and outcome. Or possibly just use the variable names as column headers?

Handing code if we want to grab the group variable names for some reason:

mtcars %>% 
  group_by(am) %>% 
  group_vars()

Or the group levels

mtcars %>% 
  group_by(am) %>% 
  group_keys()