Update 0.12.1 added the recipe for the enchantement table. You can get the achievement from now on.
To craft an enchantment table you need 4 obsidian, 2 diamonds and 1 book.Book
To craft a book you need 3 papers and 1 leather. You can craft paper out of sugar canes and get lether trough killing cows. Diamonds
You can find diamonds by mining diamond ore underground. It is mostly common at a high of z: ~11 or in deep caves. To mine the diamond ore, you will need a iron pickaxe at least, or otherwise the ore won't drop a diamond.Obsidian
You creat obsidian with water and standing lava meeting. To get it you can just look underground or take a bucket of water with you, to find some standing lava. To mine obsidian you need to have a diamond pickaxe.
When you have all the resources, just craft the enchantment table and keep it in your inventory for a while. The achievement could take up a few moments to pop.