I have been praying before meals in public since my early twenties and plan to continue. I have never felt I was abusing other people or going to suffer ridicule. Both of those are the potential new realities for living in this post-christian culture. This post by Alan Noble is a great read:
I don’t think I’ve ever felt comfortable saying grace before a meal, even at home, and when I’m in public I dread it. I try to time the prayer so that the server won’t interrupt us. The idea of a server waiting while my family prays over a meal makes me feel self-conscious and guilty, as if I were imposing my religion on them. I don’t want anyone around me to feel uncomfortable watching and listening to me pray.