一些词典上都翻译成谈天说地 ，唧唧喳喳的闲聊但一个留学生给了以下解释chit chat is a sheet or a paperwork of somekind that u can bring into a test, usually fully of formular and u know stuff, just to help u out on the test so like when someone say

"oh, there is my math chitchat