We have a few rules:-
We eat at the table and the table only for meals (im a bit more relaxed about this with snacks etc through the day)
No snacks after 4
The kids are to clear there plates and put plates in the sink afterwards
And a new rule no drinks until at least half the meal is eaten otherwise DD2 would just fill herself up on her drink
And as I'm dishing up DD1 MUST go to the toilet otherwise we will get 5 mins in and she'll need to go

Dinner is usually around 5.30-6