Transporting a 2x1x1m table is an epic task. Not only is the weight a hassle, moving it through downs and around corners becomes near impossible. To make this easier the table is design to break down into pieces. First the legs are held together with the keyed tennons (easily tapped into place) and then screwed/bolted up into the tabletop.
The first step in the process is the supports beneath the table. Four 20mm supports stretch under the table and support the thinner (20mm) fiddleback mid section to the thicker 40mm edge pieces. Slotted holes allow for horizontal wood movement while simple brass screw stay in position. Because these sections won't normally need to be removed a screw works well.
Connecting the legs to the support is a different story. These need to be able to tightened and taken apart multiple times over the lifetime of the project. Threading the wood or inset nuts are ok, but I find they wear and fail.
For this project I'm using 3/16" brass nuts and bolts. I used the leg to mark where to drill. Then counterbored with a forsner bit. With the support removed from the table I could tighten the bolt while holding the nut. Then I filled the counterbore with... epoxy. Leave to set. (Not forgetting to remove the bolt.) A quick sand and oil. And we're done.