Lay the walnut slab on top of a pair of sawhorses. One side will be intact and used for the tabletop, while the other side will be divided into four sections for the legs. Keep an additional small scrap for later use.
Measure and mark lines on the top and bottom of the tabletop for mounting points for the legs. For a stylish look and greater stability, attach the legs at an angle toward the center.
Use the Forstner bit and drill to create two large holes through the walnut where each leg will mount. The bit creates large holes so the screws will sink in deep and won’t be visible. Switch to a lag bit on the drill and create pilot holes in the legs where they will attach to the tabletop through the holes. Wrap a piece of tape 6-inches from the bottom of the bit to mark the correct depth.
Place a small amount of wax around the 6-inch lag screws so they easily screw into the hard maple. Hold the legs up in place beneath the tabletop so that the pilot holes and Forstner holes align.
Using the hex attachment on the drill, carefully fasten the lag screws into place through the tabletop. The screw will sink down all the way through with the screw head sitting beneath the surface. Tighten each set of two screws gradually so the leg snugs tightly to the bottom of the coffee table.
Place a plug cutter attachment onto the drill and drill straight into a small piece of scrap walnut to hollow out plugs to cover each lag screw. Finish cutting them out on the back side with a chop saw.
Sand down the table for a smooth finish.