Compound mortise and tenon joints on corners (ie. legs of a table)
I'd be worried about the wood splitting, especially in the beam on the right. That's only an inch or so of material to hold it firm. 

If you disassemble the workbench then the largest piece will be the surface so you only need to keep the rest smaller than that. So I suggest assembling the short side permanently. 

Then you can use a dado joint to attach the long beams and use a through dowel to be able to put a wedge in.