we're also pretty strict about sitting still for meals. if they aren't grown up enough to understand they, they go back into a chair with straps.
only big girls who behave like big girls are allowed to use grown up booster seats. those who act like babies get treated like babies and put back in the baby seat and strapped in. noise and fighting, screaming, arching or no. you don't have to be dramatic about it, just explain how it is and refuse to brook any dissent. you are the adult.
it works though.
if she refused to sit in her car seat with the straps done up, would you let her sit on the adult passenger seat and climb around the car? no. of course not. so use the same methodology here.
she doesn't have to eat, but she does have to sit up nicely, at least until she decides she doesn't want any dinner. even if that's for two minutes.
as she gets bigger, you can extend the time she has to sit nicely at the table. it's impractical to get a 2yo to sit for an entire meal as she'll get bored, but she does need to know that she doesn't have the option to carrying on playing when everyone else goes to the table. she can get down earlier, but she has to get up at the same time.
and yes, have some finger food right there so she doesn't have to wait whilst you dish up.