(I believe I've posted some pics of the 2 laptop pedestals that I made - 1 for the R/T Van and 1 for my F150 - perhaps on another thread)
This would work as well as the portable that you've shown - if it needs to be taller, a simple "sleeve" with a cut-to-size extension would do the trick.
Swivels (as nothing is glued), can be stored (but I leave it in place), the whole thing cost less than $25 and building it gave me a couple of projects to work on.
Should something bigger be required I can set-up the R/T cloverleaf table and work out of any of the 4 chairs (in the Versatile):
here it is with the laptop mounted:
and here's the one in my truck: