My favorite size is 36" X 48" too. It is possible for a table to be a little smaller if you are really tight on space. I think the Bringheli table is 30" X 45". If you don't care that the rear triangle is on the table than you can get by with a 24" X 36" with the holding post in the southeast corner.

It isn't just that you want the frame to fit over the table but also want to be able to use a surface gauge to check alignment by moving it around the outside of the frame. I wouldn't want mine to be taller than 36" because I would have to reach in more than my liking to work on the frame.