Is the following correct ? (sign in Chinese seen in Thailand) It says:
请勿餐和饮料进来
Personally I would say:
请把餐和饮料拿不进来
Actually, I don't think that's good enough. From Chinese slogans' use condition it's better to be“请勿自带餐品（食品）和饮料入内” or “禁止外带餐品饮料”