If you need something that folds up, I think the Sew-Ezi looks great -- lots of rave reviews online.
You can buy an insert for most any machine, but this does add to your cost...check them out online.
If you can find one with drawers or storage, this is a big plus.
Do think about whether you're really going to need to fold it up, and put your sewing machine & projects away somewhere...you may not need a folding table?