Do you have any information on how to do an application like what appears on the link? http://virali.se/table_booking_demo/
You code it :) Start by looking into Google Maps API, look closely into overlay (ex: https://developers.google.com/maps/documentation/javascript/examples/overlay-simple) and you should be able to do it if you have some programming knowledge. On the link you posted, the "choose table" button shows/hides some markers (you will probably strugle a bit positioning them above ground level), while "book" trigers a JS function, most probably sending and recieving data via HTTPrequest
good luck