My cutting table is a rectangular IKEA dining table that is raised on bed risers. I have a 30x42 cutting mat on it which seems to be the perfect size for me. There's enough space left on the table for me to stack fabric waiting to be cut and also the pieces as I cut them out.
I'm working on a new sewing room; at this point my plans include building in a 20 x 48 ironing surface. I can't WAIT.