I am so uncomfortable flying, from the minute I sit in the seat I am wanting to get out. My only thought would be to carry a placemat or large napkin in your carry on bag. When the food comes put your briefcase or perhaps a laminated file folder on your lap and pull out your dinner napkin/placemat and enjoy your meal.

I am one who really does not care what people think. I carry myself well and if I found I was uncomfortable with the tray a makeshift that worked for me would be just fine.

Good luck to you!