Crafting an Enchanting Table is a fairly easy task, and is something you'll most likely end up doing during the "late game", as an Enchanting Table can allow you to upgrade your tools and equipment with enchantments.
To craft one, you will need:
- One book
- Two diamonds
- Four obsidian
To get a book, you'll need one leather and three paper. Leather can be found by killing cows and horses, and paper can be crafted from sugar cane, which can be farmed.
To find two diamonds, you'll need to either find a cave or dig down to Y level 15 or below. This is the Y layer at which diamond ore begins to spawn at. You'll only need to find two - which is easier said than done!
Finally, to get four obsidian, you'll first need a diamond pickaxe and a bucket of water. Go into any cave and try and find a pool of lava. These are fairly common, especially lower down. Then, place the water next to the lava pool. If done right, the lava should turn into obsidian whenever the water touches it. Mine four of it, and make sure to not fall in.
Once you have all of these materials, you'll simply need to craft the Enchanting Table at a Crafting Table, and the trophy should pop.