So together in their Dupont Circle townhouse they have put together all sorts of cost-free tables. For years they've owned that cliche of the make-do school of architects, the table made out of the telephone-wire spool found in the alley. (The cliche of architects who have made it is the Mies Van der Rohe/Lilly Reich glass coffee table). Recently the Wiebensons found just the top of such a spool, so they added four 2-by-4-lumber legs, made from old wood ripped out of the house in remodeling, and made an outdoor table from it.