He used to call his friends daily, chat about this and that, release the tension through silly jokes, even go out with them once in a while.

this 是指示代词，表示"这个"，指代距离说话者较近的事物。 and 是连词，表示"和"，用于连接两个并列的成分。 that 是指示代词，表示"那个"，指代距离说话者较远的事物。 this and that 是一个固定搭配，字面意思是"这个和那个"，实际表示"各种琐事"或"东拉西扯"，用来指代不具体说明的日常话题。