I should just mention that despite my last post, I’m not sure how many people let their kids play with toys while they eat. It probably depends on the age of the kids and the particular setting (for example a Shabbos seudah with guests vs. a kid eating breakfast by himself).
But that’s not about not letting kids be kids, but rather about normal standards of manners. Which again would probably depend on the ages and the setting (and maybe the particular kid’s needs).