I built an enclosure base from two LACK tables, but I used one of them as a solid base for the other, with caster wheels underneath. I had 4 unused legs and decided to use one as a horizontal brace. Unfortunately, the legs aren't long enough to bridge the gap between table corners so this brace is the perfect spacer for the job.

You simply have to screw each spacer in the vertical legs, then slip another leg in between and screw it through the tabs. It will make your LACK table stiffer and you can use it as a base to attach other things.

Use #8 1.5in wood screws or a similar ISO size.