http://www.quiltingboard.com/t-112333-1.htm (see pictures)
Inexpensive Sewing Table
I had been using a plexiglass extension for my machine, but the heavier projects had a tendency to cause the extension to slide around and move.
I started looking for tables that the machine sat down in and created a flat working surface. But, boy are those things pricey.
I decided to try and built one myself. Went to Home Depot, bought 1 8ft 2x4, 2 8ft 1x6 and a 2ftx4ft