Here's an example of a table within a table. I set borders on for both tables to make the table cells more apparent.
Notice how the cells get automatically sized, both vertically and horizontally.
t1c1
t1c1
t1r1c1
t2c1
t2c1
t2r1c1
t2r1c2
t2r2c1
t2r2c2
t1r2c1
t1r2c2