Now that Mayor Bloomberg has announced a competition to build 250 square foot micro-units, TreeHugger is going to show you how to furnish it. This folding table found on NOTCOT might fit the bill; more like a picnic bench, it includes both a table and seating. at 70 cm (2'-4") long it is only going to seat two, which is a shame. Folded up, it is only ten inches deep, so you could store two of them in a pretty small space.
It's called the Klapptischbank Up Up Up, from Germany's Magazin. Unfortunately it is made from Afzelia, or Doussié, which Rainforest Relief says should be avoided entirely.