About a year and a half back I built the current table in my garage. It has served us well in it's time and I have even built another one since then that was supposed to be portable. The 'portable' table consists of two saw horses and a sheet of 6x4 MDF framed with 1x1. It is pretty sturdy but it is hard to transport without a truck.
This has led me to my latest gaming table endeavor - a portable gaming table that can be hauled around in the back of a Prius.
The directions and ingredients for this table is very straight forward -
You need two folding card tables and one sheet of hardboard cut into 2 foot sections at your hardware store.
Open the tables and lay the hardboard on top of it.
And presto - instant portable table.
I have used this table once in a few games against Big Al and it was a lot more sturdy than you think it would be. We draped a sheet over it and clamped it on with some paper clamps and it worked like a charm.