Explanation: The Emperor Claudius was a huge nerd, which is why he's my spirit animal and favorite Emperor (he also had a stutter). He wrote a series of texts, including an Etruscan history, a dictionary of the Etruscan language, a history of Carthage and the Late Republic, and a book on gambling/gaming. None of these have survived, despite that even one of them would be a huge boon to modern historians. Most important of all, though, would be the Etruscan works, which would be the equivalent of the Holy Grail for Etruscan studies, to receive a work by a scholar alive when Etruscan culture was still alive (if no longer dominant) and a book of their language? There are academics who would literally kill for that.
The joke here is that the best use of a time machine, therefore, is to go back with a copier and make some reproductions of dear Uncle Claudius's work!