Get an A2-sized paper grid map (FAR cheaper than laminated) and then get an A2-size piece of that plastic sheeting they use in cheap restaurants to protect the tablecloth (about 1.5mm thick transparent, soft plastic).
That's what I use (well, mine are bespoke to fit my table) and not only does it give me RPG-related grid map capabilities, it's also good for holding board game boards and displays in place, protecting them from drinks and food stains, while giving a surface that you can write on and that gives good grip for playing pieces.