What information report server tempDB store to support the reporting services?

Report Server TempDB store following information

1. Information about the session of users connected with reporting services via Report Manager.
   
2. Information about the cached report that means report which are partially cached to stop the round trip to database again and again.
   
3. Certain work tables generated by report server.
   
4. Report server temp db does not contains any persistent data. So, you can delete it as well. However, in order to recreate it you have to re-start the reporting services and then execute the catalogtempdb.sql script to add table structure.