I have my table set up pretty much like this video:
http://www.youtube.com/watch?v=g14go...feature=relmfu
I have a 4' fold in half plastic table against the wall, with my 40" machine table, which I bought from Leah Day, in front of it, which makes it 4'wide x 45" deep from front to back. Then when I want to quilt I have another fold up table which is 24"x4' which I put on the left side, so now my setup is 6'wide x 45" deep. I hope this is clear enough.
When I am done quilting then the table folds flat and I can put it out of the way, and I still have 4'x45" to sew or use my embroidery machine. And I keep my Viking, Janome 300E and my Brother 1034D Serger lined up on the back table when not in use. Works for me.