he is just a toddler who is learning about food, and is reacting as all toddlers do because they think they are the centre of the universe and EVERTHING, including food is there for their benefit only.
You have to do one or all of three things -
1. Distract - with toys, books etc. to take his one-track mind of the bread rolls etc.
2. Remove - take him out of the situation, which you did do at the wedding.
3. Be consistent - and don't give in to the tantrums if you know that he is full etc.
There is nothing embarrassing about this - don't make this about you! He is not doing to wind you up! Really!
its a phase - if he was 6 years old, I might be a bit but he is still only a baby! He will grow out of focusing all his attention on food, and choose something else to focus on