Ema san is right it's a general rule the place where a lot of people seat(thriving) is good to enjoy! Don't worry too much about perished food it's better now but if you're allergic to msg then have medicine with you.
Water bottle is very cheap there buy domestic one like Lavie or asked the front desk to deliver to your room a 5 litter water judge it is cheap to us$1 or little more. Make coffee or tea with it too!