Final answer:
Using a tray to carry out beverages provides stability and helps to prevent spills and accidents.
Step-by-step explanation:
You should use a tray to carry out beverages when you need to transport multiple drinks or when the drinks are in containers that are not stable or might spill.
Using a tray provides stability and helps to prevent accidents. For example, if you are carrying multiple cups of coffee, using a tray can keep them from tipping over and causing a mess.