A joke/meme from Tiktok, popular among kids and teenagers, some adults pick it up for content too.
According to some comments from TikTok, it means that a friend of Kai Cenat, takes a portion of food from Kai and his friend as tax since he likes food.
Kai Cenat had a friend come over for dinner, and unexpectedly his friend experienced a fanum tax initiated by Fanum.
Man, the way he took food from us looked like it was a fanum tax.