The following plan is another one from American Woodworker Magazine. Wordbench plans seem to be some of the most popular on our site. Everyone needs a workbench or 2 and a portable (folding) unit can be ideal. The key is to have a unit that doesn’t sacrifice stability for the sake of the portability.
This plan is limited unless you purchase the back issue, however, for most woodworkers, you should be able to figure things out based upon the material list, cutting list, and photos.
Click on the picture above for the full plan at American Woodworker. You can purchase the back issue from there if you are having trouble with the plan from the linked page.
Good luck with your portable bench.