I am not sure. It is possible that Q would not have a noun directly corresponding to E 'fun' but several words used when talking about different aspects of fun. If you think of fun as amusement, then tyalie comes the closest as it is glossed as 'play, game, sport, mirth' ('sport' itself comes from 'disport' = 'diversion, amusement, fun'). Then there is alasse, lala-, nnn.

+Tamas Ferencz thank you, Tamas. Perhaps you are right. Now, can you please tell me what is the difference between those various subdivisions in this group: Wordwheel, Koirëa Quenya, Quenya Chat, Discussion?

+Ицхак Пензев good question:) Quenya Chat I set up explicitly for chatting about anything in Quenya. WorldWheel is for musing about individual words, either looking for a neologism or just the meaning/structure of an attested word. Koirea Quenya was intended for discussing approach towards NeoQuenya, plans, "policies" etc.
'Discussion' is the default category that is created by Google when you set up any community.
But I certainly don't treat any of these as rigid boundaries; as there is no more than a dozen of us who routinely and actively post here I think we can handle the stream of posts however it is structured.