Thanks for all your responses so far!
I've been using the dining room table (too short!) up till now which is 3'6" X 6'4".
I'd like it to be just a touch wider I think. But Donnajean has a point of not being able to reach in the center of it. I do like to lay tools and cloth on the top as I assess and reassess my quilt.
Yes, I am planning on being able to walk all around it with anti-stress mats on the floor.