I recently finished this black walnut table for my wife. It's about 4-1/2 feet wide and 13" deep. The top is a single piece 1-1/4" thick. The "apron" is three layers (1/8" thick each) laminated around a curved form. The apron rests in a 1/2" deep groove routed into the bottom of the top with clips holding it in that allow for seasonal movement. Concealed clips in the back edge of the top anchor into the wall studs. Near the bottom of each end of the apron, 3/16" brass pins extend 1/2" into the wall (plastic anchor sleeves driven into the plaster) to keep the apron from shifting around.
The finish is just two coats of 50/50 boiled linseed oil/mineral spirits followed by 4 coats of gel varnish.
It's surprisingly solid. I can lean on it pretty hard with no movement.