Obsidian Tables are decorative pieces of furniture that can be crafted in your Crafting Menu (opened by "Q" as the default key) or at Crafting Tables in older worlds. The crafting-recipe for Obsidian Tables will be unlocked by taking/crafting a Stone Table for the first time, which in turn is unlocked by taking/crafting a Wood Table). To craft 1 Obsidian Table, you'll need (as of R26 in December 2015): Crafting/taking an Obsidian Table for the first time will unlock the crafting-recipe for Iron Tables.