Technically yes, ancient tolassian tomes are unlimited since they can be dropped by rumor bosses that are also unlimited.
But since tomes have a very low droprate and rumor bosses spawn very slowly, it's not really recommended to try and hunt tomes that way. You would need to be very lucky to even get a single tome after grinding them for a long time.
If you still want to go ahead and try it, I would recommend that you do it by killing the two dragons at the end of the Icemist Underlevels. They also drop rumor boss loot but are a lot more reliable to farm then rumor bosses. But even then it might take a while before you even get a single tome from it.
