Foodtime with the family

My grandfather and my whole family will have dinner soon, when everybody arrives :) But I don't get why we are doing this, cause this is not something we use to do. Everybody eats whenever they want, not at the same time or anything. And today isn't even any big or special day, so I don't get why we are making such a big deal of this? :D Anyway, hope they will arrive soon. I'm starving.
We'll eat fish and potatoes + tofu :D And I'll ofcourse drink milk, I don't like to drink nearly anything else ;). And I've heard that milk is super healty! :D