clever design table or bench

Many years ago, for my first home that had a small covered patio, I built a pair of patio benches that converted to a picnic table -

- very similar to this :

All 2 x 6 pine ; looked nice, worked fair ; eventually became a bit too wobbly for a table but OK as benches. Sorry - but I can't really imagine any indoor furniture situations that would benefit from these.. even if they were better designed and better built. John T.

well wobbly can be fixed but usually that has to be inherent in the design and implementation

a playroom or a workroom that could do double duty

it could be taken a step further and fold up again so it has a smaller profile then the bench

Agreed. I had a couple of sets of those, though the "frames" were structural plastic (foam?), with 2x4 seats and 2x6 tops. I used them for seating around the pool and, of course, they made into great picnic tables at meal time.