Our food rule: We'll serve it to you, if you want it: eat it. If you don't want it you can wait until we are done eating and have apple sauce, (scrambled eggs- depending on the kid, if it is a child that really needs the protein we'll gladly cook up some scrambled eggs
), or PB bread.
Usually they'll try it while they wait for us to finish eating. The Words "yuck, gross, disgusting, or awful" are not allowed at the table. It's okay not to like it, but you may not bad mouth some thing we worked hard to prepare. You can say "I don't think I like this kind of food". If they use impolite language they are excused until the meal is done.
They also have to sit at the table and remain seated until they're done, they can get up and leave if they're done though as long as they clean their hands and face before they leave the kitchen.
Eta: we don't do dessert or anything sweet after dinner unless it is a Birthday. We usually eat dinner late and they go right to bed (or into that routine) as soon as we're done. They often eat a large snack/meal at 4.