In order to make a Crafting Table you first need to harvest one Wood block from a tree.
Once you have at least one block of Wood in your inventory press
to open the crafting menu and craft the Wood block into Wooden Planks, one Wood block crafts 4 Wooden Planks.
Once you have your 4 Wooden Planks you can craft your Crafting Table.A Crafting Table requires 4 Wooden Planks
Here's a video showing you.