The book is for enchanting items on the anvil.
To make an anvil you need 31 iron ingots. In a crafting table grid, place 3 blocks of iron across the top, 3 iron ingots across the bottom, and an iron ingot in the center:
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Then place the anvil, use it, place an item in the first slot, the book in the other. The enchantment costs Experience levels too (and you gain these gathering experience spheres by killing monsters, mining minerals, and smelting items.)
For example, a book of Sharpness III used on iron sword will make the sword cause 1.5 heart more damage on each hit.
You can enchant normal books too, using enchanting table - which might seem useless since the resulting book will have only one enchantment and you'll have to pay the exp cost twice (first, creating the book, and then again, enchanting the item with the book on the anvil). The serious advantage though is that the enchanting table gives enchantments randomly while the book gives the item exactly the enchantment of the book.
Imagine you want to make your diamond boots to have featherfalling enchantment. You can waste 40 diamonds on enchanting one pair of boots after another on the altar until you finally get the featherfalling - or you can use up a bunch of leather and paper until you get a book of featherfalling, then just apply it to a single pair of boots - 4 diamonds total.
I managed to find a solution to the problem.
After you pick up the book from the Inscription Table, you have to open it by placing it in your hand and right clicking. Then give it a name and click the 'sign' button. Then the book image looks like an enchanted book and can be placed on the lectern to craft the spell.
Best Answer
This youtuber did a walk-through and I think he tells you where to throw the books
Click 'Watch in youtube' - The youtube icon
That is a series consisting of 8 videos, you should be able so see them from the sidebar.
Fast-forward the video and you should find where to throw.
Otherwise if you don't feel like watching the videos, just simply use some X-ray mods to find hoppers or such items. If you don't mind hacking. You could use some other mods too but the x-ray was the only one that came to mind.