To dream of an eating contest may reflect competitive waking life situations. Competing to see who can do more or experience more of something? It may also reflect you or someone else that is showing off with how much of something they can do.
Consider the food for additional meaning.
Example: A young man dreamed of having a strawberry eating contest. In waking life he was having a bet with a friend on who could sleep with the most girls by the end of the school year.
Eavesdropping might even reflect how nosey you are or even point your use of the Internet to research someone.