Jointery
The function of the tools I use and how they work are explained here. Specific tools used are noted in bold.
The legs are attached to the top and middle shelf using floating tenons. Tenons are rectangular domino shaped pieces of wood that fit into slots which are cut in the legs, tops and shelves. The slots are cut using a multi-router. The spiral router bit turns at high speed which cuts the wood. The multi-router allows the router to be controlled over X-Y-Z axis, thus allowing for precision cutting of the slots.
Before the slots are cut, the table is temporarily assembled and leg positions are verified. A temporary top and shelf are used in this process. The slot locations are then drawn in pencil on the legs.