Below table switch machines

Drill an appropriate size hole through your table top, and insert a short piece of small brass tubing into the whole. Then using the appropriate size piano wire which will easily fit through the small brass tube, bend the piano wire to operate the switch point throw bar, stick the long end down thru the tube, and make the appropriate bends to connect the piano wire to a switch machine.

We also used Tortoise switch machines. The mounting process is very similar. With the Atlas machine, you can use tape to hold the machine temporarily while you adjust the exact position. You can make a jig for the Tortoise machines to assist in moutning. Do a search on Youtube and you'll find many helpful videos on the "how to" and different ways of doing it.

A bunch of Tortoise located in the general area under my small Service Yard, plus the yard entrance turnout and double crossover switches on the dual mainline. Older units from the early '90s recycled from a 15x25/8/12 layout I dismantled in Oct. '09.

You can also use the NJ Dual Coil switch machines with the RixRack mounting bracket.  I have used about a dozen of these.  They work great and are easy to install.  Very similar to the tortoise machines.