This has been bugging me because it seems counter-intuitive. Why do some tables have long, wide tenons? I'm talking about tables that have, for example, 3" wide, 1/2" thick, 1-1/2" long tenons on the aprons. Is that really necessary? Dining room chairs are very often joined with two 3/8" dowels at each joint with depths of 1" on either side of the joint. That seems sufficient to hold 280 pound Uncle George and he no doubt weighs more than all the dishes and food on the table.