I removed the column from my 6x7 enlarger and mounted it to a sturdy plywood cube, which has a wider base than the top and sides. The base has 1/4" holes on each side, and the edge of my worktable has 1/4-20 threaded nuts in the surface (T-nuts). When I want to print big, I mount the cube to the edge of the table using 1/4-20 thumb screws and put my easel on the floor. For normal printing, there's a set of holes at the back of the table.
A cool thing about this setup is that it's easy to fine-tune the level of the enlarger; I can loosen one corner and slide a shim beneath it and re-tighten. Works like a champ.