We've always had dinner as a family. DD1, when she was little, basically didn't eat dinner. She grazed all day, and had very little appetite at dinner. So, she had to sit with us to start the meal. If she felt like getting up, we let her. If she wanted to talk to us, we told her to come back to the table. If she was doing something distracting, we said, "we're eating right now - that has to wait until later". Even though she didn't have to sit with us for the whole meal, she figured out that mealtime was mealtime, not "run around and be crazy" time.
I've never enforced any kind of "stay at the table with us" rule. But, they have to eat at the table, and ask to be excused (I actually don't care for this, but it's important to dh). They're allowed to come back - once - if they decide they're still hungry. DD2 has no dinnertime rules, aside from not yelling, and she can't 'take food away from the table. Over the next couple of years, we'll tighten up the same rules as the older kids. Basically, those rules are to be at the table at the beginning of dinner, don't interrupt, use basic table manners, such as not taking all of your favourites from the serving dish, asking politely for dishes to be passed, eating reasonable sized mouthfuls of things (ds2 still has trouble with this), and ask to be excused before leaving the table.
They also have to try things they don't think they like, but only one bite. If they genuinely don't like what's on the table, they can get a sandwich, piece of fruit, boiled egg, or whatever, from the fridge. I was a picky eater, and people's constant attempts to make me eat things I really didn't like caused me a lot of issues with food avoidance, in addition already disordered eating. (In my case, I now realize there were sensory issues involved, and I know dd1 has them, too.).