Add an enchanted book to a loot table

You can't do this with the MCreator software. However, it is quite easy to do by making your loot table, then changing the code (the ID would be enchanted_book{StoredEnchantments:[{id:*name_of_mod*:*name_of_enchantment*,lvl:1}]} (delete the *'s in there as well).

For example, with a custom curse from my mod, I would do enchanted_book{StoredEnchantments:[{id:brine:drowning_curse,lvl:1}]}