The smooth, flat slabs normally used as stepping stones last for years under any weather conditions -- a quality that makes them ideal as outdoor tabletops. The stones (actually made of concrete) can be found in a variety of shapes and colors at most home-supply stores and garden centers. To make a pedestal table, choose a heavy terra-cotta urn for the base and a paving stone for the top. Place the urn on level ground, right side up or upside down, and then top it with the stone. The weight of the stone will hold the table in place, season after season.
Martha Stewart Living, March 2002