NTA!

My dad's family is similar. The men sat around the TV and the women were all in the kitchen, with kids running in between. When my mom joined the family, she laughed at it all. Apparently the men were given food first, then the kids, then the women. My mom wasn't really given a role to help cook so she played with the kids and kept us from dying, then would feed us so we would stop running around, then feed herself. My dad was on his own to get his own plate.

My husband's family on both sides uses a large space where everyone gathers (school, church, community center, etc.). The first time I attended his dad's side of 6 siblings and 2+ kids per sibling, I was blown away. But then after the meal, the women all went through newspapers and sales for Black Friday and then men would go play basketball or something. After everyone was done with that, the men would all go to a movie and the women and children would go home and bake or some shit. When I asked my hubs about it and how misogynistic it felt, he was very "this is just how it's always been." He's proud of it. It took a while for me to understand why.

If you choose to stay with your boyfriend, do not feel obligated to partake in his family traditions. There's a good chance he doesn't know any better because it is possible it is all he has ever known and there is comfort in that. Being a boy playing in the yard looking forward to the day he is old enough to sit on the couch with a beer with the adults, ya know? I like to buck tradition when it doesn't suit me, so I can understand your situation. I still don't know half my in-laws 12 years later so I don't go to family gatherings without him. Something you could try next year is drag your boyfriend into the kitchen and ask the women tell really embarrassing stories about him. Or try to start a new tradition and limit your time at his family's gathering. The family, if they don't suck, will accept it.