I have a really nice 6/8 seater beech effect topped extendable dining table with detachable chrome legs - not fold up as you ask for but easy to store away.
Very solid. originally £200 from John Lewis.
£85.00 plus chairs if also required @ £15 each
E mail me if you require photos and diamentions. Live SW18 (Southfields grid)
Am just about to advertise it on Forum and Gumtree.
gail@gailmac.com