Unlock the usefulness of the Uncrafting Table with that ridiculous recipe, eight crafting tables and a Maze Map Focus. How do you even cram all of those tables into a single one? Anyway, some say that recipe is temporary and that the bench may be a prize from some quest or monster in the future. What does that even mean? Maybe you should make one now while you have the chance to do it with minimal effort. The Uncrafting Table looks like a normal Crafting Table, but it has an input slot. The input slot gives you new methods of manipulating your existing items. You can craft like normal with it if the input slot is empty, but by placing an item in it, you can use the new functions, which I'll call "uncrafting", "repairing" and "recrafting"! Of course, you could use it for crafting, but why do that after you just built eight Crafting Tables?
Finally, a use for those golden hoes that skeletal druids drop. Uncrafting lets you take apart items into their component ingredients. It only works on shaped recipes. The ingredients are shown slightly gray when they are still part of the item. When you pick one up, it will consume the item and fill the bench with the rest of the ingredients. Uncrafting costs one experience level per significant ingredient. What's significant? It seems to be everything that's not a stick.
Repairing lets you repair tools and armor piece-by-piece. When you place a damaged item in the input slot, you will notice that some of the ingredients are marked with red. Those ingredients are damaged, and you won't get them back with uncrafting. To make the item whole again, put new items (iron ingots, or whatever looks broken) into the crafting grid to replace the damaged parts. Items can only be repaired fully. Repairing normal items is free, but repairing enchanted equipment will cost you experience levels. The cost is shown on the right and is charged when you pick up the finished item.
Recrafting is mostly useful on enchanted equipment. It lets you remake an item into a different material. To recraft a tool or piece of armor, place the original item in the input slot. Then, put the new materials in the crafting grid until you have replaced all the old materials. Pick up the new item from the output slot to seal the deal. Recrafting will cost you the original item and the new materials. Recrafting an enchanted item will also cost you experience levels. The cost should be roughly what you may have paid for the enchantment in the first place.