Ya- if you stop for a full-on lunch at the turn you're gonna have to wait for an opening to get back on the course . .or ask the starter if he can re-insert you if the course is packed.
Definitely a better plan to have a meal before or after your round. I have dropped playing partners because they take too long at the turn (not mid-round . .but I don't call them to play again). Even the hotdog grabbers get on my nerves. Heck . .even the guys who stop the cart girl more than once or twice get on my nerves, lol. Are we here to play golf or to eat and drink?