Join Date: Dec 2015
Location: The Very Tip of Lake Michigan
Actually attaching it to the wall is a game changer. You would/ could eliminate three of the legs and an entire length of skirt (both along the front) if you wish. Simply scab a ledger board across the wall with a few strategically placed anchors in studs and attach the table from underneath to hide the fasteners. Then you need but two legs for the rear of the table and three skirt boards to give it eye appeal and strength in the back. As someone has mentioned, a solid core door would be the ticket to a very robust table that would be unlikely to sag. However, a door would certainly be thicker than 3/4" (and I would still wrap a skirt board for aesthetic reasons).
Almost every table made has some type of skirting for stability (legs normally attach to the skirt boards in some fashion), and some skirts are wider than others. Your width would be whatever is pleasing to your eye, but I'd go not no less than 2 1/4" for a 3/4" top. Less would be O.K. if you use a solid door.
Another $000,000,000.02 worth of advice,