tableworkshop
Below is what I have. There are small pre drilled holes but I can add more or make the existing one larger. What is not shown in the picture is the fact that the legs are foldable.
My plan is to build a table for which I should be able to quickly replace the top. The tops will be multipurpose: router table, a table with t-tracks and holes for bench dogs and a table for jigsaw like in the second picture
Update: here is a bottom view of the frame and the top attached
As it appears the 'wobble' is between the metal leg, the metal bracket, and the bolts provided, I'd say this wobble is due to IKEA's ahem rather wide tolerance specifications.
In other words, sometimes you just get wobble when it comes to IKEA products. :)
I'd suggest using something to solidify the connection between the leg and the plates. JB Weld would be a possible option. Mix it up and put a generous amount between the leg and bracket, then tighten up the bolts. Let it set up for about 24 hours and you should now have solid material between the two parts to shim the wobble away.
As long as it is not a V8 engine block it should do fine. If you hammer anything on the surface, stay near the legs, toward the center you will feel the slight springiness. It will not let anything you are driving with the hammer, like wood chisels for example, will not perform like they should. That particular task may even be a bit unsafe over the span.
Use a cleat on the back edge at the wall so the hinges do no supporting when the top is down as a work surface
I added a sketch to help understand the cleat I wrote about.
Best Answer
I would construct the table tops with an extra layer of 3/4" plywood or MDF on the bottom that is designed to just fit inside of the inner rectangular shape of the frame. This will align the top with the frame and keep it from sliding around on in a horizontal direction. With that in place the amount of hold down force that you need will be minimized.
One method to provide the hold down force would be to make some swivel blocks that are mounted on the bottom of the table. These would rotate on a single screw/lag bolt including a washer. The idea is that one end of these would be able to rotate to be under the edge of the table frame. You could cut the surface of the block that engages with the table frame at a slight taper so that the block tightens up as it is rotated.