In your questlog under The New Frontier questline you'll find your Tome of Knowledge Counter if you scroll all the way down. I'll attach how it looks in my questlog, where you're able to see that I've delivered nine of them.
Loqhakk - Applying to TibiaQA team as ModeratorJuly 26, 2024
Nareull - Applying to TibiaQA team as ModeratorJuly 14, 2024
Looking for new TibiaQA staff membersJuly 12, 2024