I had a similar thing with Ava. And then she wouldn't eat her breakfast. What I do now is when she wakes up I give her a sippy cup of milk and then just let her do whatever. Watch some cartoons or read or play and then after about 1/2 - 45 mins give her breakkie. Now there aren't any tantrums and she eats all her brekky. Think she's like me and just can't eat the minute she wakes up
I do the same with DS2. I can't eat as soon as I get up, I need a cuppa first. My boys are the same, so I give them a cup of milo first. DS2 goes off and plays for a while and then is happy to eat his breakfast. He eats his brekky at his kids table and chairs set and is very happy. Maybe this is something worth trying instead of sitting him at the big table?

Good luck