People ensuring you pray before a meal is preaching.
Yeah I usually just look like I'm participating, then when everyone else has their hands folded and eyes closed I stop.
Doesn't really help with one of my aunt/uncle and their kids, who do "fun" prayers with all sorts of waving your arms about and other ridiculous things, no doubt to draw the kids in. I wouldn't want to do it even if I was religious.
forced participation
Yeah, every religious family I've ever had dinner with will, at a minimum, continue without and give you dirty looks before and after if you don't participate. Most won't do it without you, and will all sit there looking at you until you join.