If you get a expensive professional hollow chisel mortiser the table will tilt on a angle to mortise like that. Building one table you could mortise it the 18th century way. Drill out most of the material on an angle and hand chisel the rest of it. As thick as the timber is the tenon is probably 1" thick. The joints would be stronger if glued together with a glue such as Titebond III but would be stronger if you put pins in there too. If you manage to make a good tight joint the pins would only help a little if you don't like the look.
Last edited by Steve Neul; 07-02-2013 at 08:04 AM.