Here's an interesting joinery method: Mexican designer Emiliano Godoy's Polhem Table, which ships flatpacked, employs something like external dovetails to stitch the legs together.
While it might take some time to fit each key in place, I'd say Godoy has rather brilliantly designed an instruction-manual-free, idiot-proof assembly method. I believe that even the most mechanically-challenged person would easily figure out which pieces go where.
Godoy refers to the keys as "padlocks." Here's his description of the table, which also shout-outs his inspiration:
This dining table has simple lines that contrast with padlocks in the same material but in a different color. These padlocks are the ones that structure the joint between the boards in a perpendicular way.
This allows transporting and storing the table flat. The two-way locks prevent the table from coming apart or loosening over time.
The table's name honors the Swedish inventor and scientist Christopher Polhem, who is credited with one of the most important innovations in the development of modern padlocks.