is this rude?

We live together as a family. Every night I cook dinner and every morning I cook breakfast. When it's done I will set everything out and make drinks for everyone and plates. Me and our son sit down to eat and he is walking around doing other things until his food is cold almost every time. Then by the time we are done eating he is ready to sit down and eat. Mind you I tell him 30 mins prior to dinner being ready that it'll be ready soon. I'm sick of it. It pisses me off its the only time during the day we actually have a chance to sit together and talk about our day. Is this rude or am I over reacting?