This is a common question in Spanish, and it can be used in a variety of contexts. For example, you might ask this question to:
* Find out what someone has in their room: "Que hay en tu cuarto? Do you have any books in there?"
* Express interest in someone's belongings: "Wow, your room is really cool. Que hay en tu cuarto?"
* Start a conversation about someone's interests: "I'm going to decorate my room. Que hay en tu cuarto? Any advice?"
It's important to note that, like in English, the tone and context of the question can influence its meaning.