Beveled bottoms for oversized tabletops

I've glued up a large tabletop and I want to cut bevels on the underside to give it thinner edges and a more delicate look. Because of the size and weight, I don't think I can manage it safely on my tablesaw or router table. Can you help?
—John Gill, Tyler, Texas

Start by constructing an auxiliary router base with a fence mounted to one edge, as shown above, John. Then, cut three rails of ³⁄₄ " MDF slightly longer than the longest dimension of your tabletop. The jig will ride on these rails.

Using double-faced tape, attach one rail to the edge of your workbench and slide the table against it, as shown above. Tape the other two rails together and attach the stacked rails to the tabletop about 6" from its edge. (You can alter the angle of the bevel by changing this distance.)

With a straight or spiral bit mounted in the router, make a pass along one end of the tabletop. (Starting with the end-grain reduces tearout on the edges.) Double-face-tape a ¹⁄₄ " spacer to the jig's fence and make another pass. Continue the step-and-repeat process, adding spacers and making passes, until the bevel is completed. The bit will nibble away some of the bench-mounted rail on the last pass. Then, rotate the table, remove the spacers from the jig, and repeat for the opposite end and then the edges. Finally, sand the bevel smooth with a sanding block or your random-orbit sander.