( NAmE , informal ) used when you are stating that there is nothing more that can be said about sth or that sth is completely finished
THAT'S ALL SHE WROTE
Meaning of THAT'S ALL SHE WROTE in English
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005