Have you seen the commercials for the Table-Mate II on tv? I went to their website where they offered buy 2, get one free. The nice thing about the design is that the support legs can go under your mattress while the table ht can be adjusted up above your feet. I'm using 2 in the back of my Toyota cargo van, held in place by a queen futon mattress. I've secured the top of an oak coffee table on them which gives me a place to put a mini-fridge, microwave and tv. The 3rd one I've got next to me on the side of mattress. The top folds down flat so out of the way until I need it for eating, reading, writing, etc. Just the right size for a small space.
Regards,
Wade