I don't like to talk business over lunch.

talk 是动词，意思是"谈话、交谈"。 business 是名词，意思是"商业、生意"，指与工作或交易相关的事务。 talk business 是一个固定搭配，意思是"谈生意、讨论工作事务"，特指在非正式场合谈论商业话题。