...huh. The assistant seemed really concerned about her not drinking too much. Could she somehow be aware of the resurrection and alternate history?
No, more about the fact that these types of dinners where drinking is involved can be dangerous, at least as far as what I've read in mangas and LNs. There's a few tropes in play;
1. Women can't typically hold their alcohol - which considering the expected body weight of female actresses probably isn't too far off the mark considering the next point.
2. Men/producers/investors will force drinks onto the women/actresses that they can't refuse because it would be "rude" to decline a drink from someone of higher standing. Take in 5-6 drinks within a short time period and most people would be feeling it. So unless you have the backing or ability to refuse the drinks, they can add up.
3. While it is a dinner, it could be unsightly if you are seen eating too much (to help combat the effects of the alcohol) so you eat lighter foods and generally snack.
Combine all of these and you have a recipe for disaster and potentially career ruining events. You could pass out during the dinner, you could get taken advantage of while intoxicated, your image in front of these influential people could be tarnished, you could be forced into a compromising situation or maybe all of the above. Hence why the assistant is worried.