In Parshat Ki Tisa, after the golden calf, Moshe pleads for God to forgive them, saying if not, blot me out of your book. The text then says:
33 And the LORD said unto Moses: 'Whosoever hath sinned against Me, him will I blot out of My book.
34 [...] nevertheless in the day when I visit, I will visit their sin upon them.'
But on the day I make an accounting, etc.: Now I have listened to you not to destroy them all at once, but always, always, when I take an accounting of their sins, I will also account a little of this sin with the other sins. [This means that] no punishment befalls Israel in which there is not part of the punishment for the sin of the [golden] calf. -[from Sanh. 102a]
So clearly God punishes, but this doesn't sound much like "blotting out". After all, we have the torah text, including the names of some of the participants and the descriptions of their sins. What does it mean when it says God will blot out people from his book?