This is a mount for a virtual pinball board made by CSD.  It allows you to put less wood screws into your cabinet and easily remove the board for service/replacement and I think looks a little more tidy in your cab.  I put 6-32 threads in, but they don't print very well being so small.  You can either run a 6-32 tap through the holes to chase them, force a 6-32 screw in, or just use a #6 wood screw (½").  I chose to run the tap through and it works very nicely.