Connect panel mount switch to PCB
I don't think you need to use a terminal block, if you don't need to be able to rapidly remove and replace the switch.  
If you are having the PCB made by a PCB manufacturer that will provide plated through holes, then three of those spaced 7.1 mm apart will provide good mechanical strength attachments to the tabs on the connector.  Just specify round holes that are large enough for the pins to go through.  So, the finished diameter of each mounting hole will have to be at least...


$$d = \sqrt{0.2^2 + 4.8^2} = 4.804 mm $$

Plus add a little bit extra for manufacturing variance. Also note that the through-hole plating reduces the inner diameter of the hole a little bit, by perhaps 0.125 mm, although many PCB manufacturers will take this into account so that you don't have to when you specify a hole size.  


There are of course switches designed for mounting right on a PCB, but if you want to use this one, then big through holes for the tabs to go through is probably the best way for a cheap hobby board.  A plated through hole rectangular slot would match the shape of the tabs more closely for perhaps better mechanical location of the switch, but for a hobby board, round holes are probably good enough for what you want.