daily tea rice thing
a common or daily event
It comes from the fact that many Japanese people eat rice and drink tea almost every day. Sometimes it is used ironically to indicate a negative incident that is not supposed to happen frequently. For instance, “残業は日常茶飯事だ” means “working overtime is like an everyday event”.
Note that while 茶 usually reads “ちゃ”, it reads “さ” in this expression. This reading is used in a few other words including 茶道 (さどう, “tea ceremony”) and 喫茶店 (きっさてん, “cafe”)
Isn’t it great that we can have BBQs on campus??
Well, it is very common here in Australia.
It is quite usual that he comes late.