http://www.bangkokairportonline.com/node/86here is a really useless map where it is hard to see and understand everything. It has the suggested meeting place, but from memory there are no seats there and not much room and so it is completely not suitable.
Hang on I will see what else I can find:
http://www.airportsuvarnabhumi.com/Internal_Airport.pdfHere is the same map but with some better explanations. So the restaurants I was talking about were on level 1 and 3.
http://www.airportsuvarnabhumi.com/about-s...port-vdo-guide/Here is a video guide.
http://www.toursuvarnabhumi.com/suvarnabhu...port_layout.phpMy computer didn't show that one, but maybe yours will and maybe it is useful?????
I think either tell your friend that you'll be in one of the restaurants on level 3. Then get there and find one that has some room. He can walk around and find you easily - it only takes 5 minutes to look in all the restaurants there.
Or, tell him to meet you in the restaurant on the bottom floor. You walk out to your left, go downstairs and go to the furthest left hand (left as you are walking out of the airport) end and you'll find that restaurant. Only disadvantage there, is that there is no waiting service, so you will either have to try take your bags to the counter to order something or leave them unattended while you order. The upstairs restaurants will (I hope) come to your table.