They have a paternal uncle who has a bad temper, Handa always uses his brains to avoid work being given to him by his uncle (Pisemosai in Bengali) Handa also often tricks Bhonda in doing stuff that would get him a scolding or thrashing from pisemosai but at the end of the story he invariably ends up getting beaten himself.
This passage describes a dynamic where Handa, through cleverness and deception, tries to evade work from his uncle, Pisemosai, who is known for being harsh and prone to punishment. However, despite his attempts, he always ends up getting punished himself.