60 chapters in a single file is a wee bit excessive
Sigil split that (at 50) and you are good to go for another 50.
I don't think TOC was intended to be used like that.
You might look a Calibre (you can create a book-less "library" from an ISBN list. what I do for my dead tree collection) .
There is a

"Catalog" that can be built out of the meta-data.