That sounds like a pretty good idea for some. But, I prefer one big table, made exactly straight plum, and level. I use it quite frequently as a reference for jigs, wing building and such. Also, my shop floor is quite irregular, so, moving and joining tables would require a bunch of adjusting each time I decided to use an additional table.
That being said.... If I were working out of a smaller area, (ie: garage), I think it would be a good idea.
Nothing like being wish-washy, huh?