In other words, in fact, it is enough to put two floors on the enchantment table, no matter how high it is. If the two squares are far apart, you must also ensure that the space between the bookshelf and the enchanted table must be air, so you must not put anything between the bookshelf and the enchanted table, even if it is only a torch.
Influence of enchantment on enchantment platform
In the enchantment stage, you need to find some obsidian, which is naturally generated at the position where water flows into the magma source, and you need to collect it with a diamond pick. Be extra careful when mining obsidian, because magma often appears below and around obsidian.
Diamond mines are produced in the world below 16, so it takes two diamonds to dig to the bottom of the world. Collecting every diamond ore with a pickaxe will drop a diamond, and the diamond will be affected by the enchantment of fate.
Use sugar cane to synthesize some paper or, find some in the box in the fortress library. You need enough lapis lazuli to provide raw materials for the enchantment, so you'd better make some preparations before you start.