What is it about Christmas tree ornaments that sends cats into destruction mode? It's like they all have big signs on them that say "annihilate me!"
So back in the 1400s, instead of fixing page tears in a panic with tape, they would embroider them together with silk. This is probably the classiest response to a problem that that era ever had.
"The pages of the book are made of parchment and they show typical damage in the form of holes and tears that happened while the parchment was being made. Some time after the book was copied, the holes and tears have been mended artistically with silk of various colours, mainly in blanket stitch as used in embroidery."