The Project Table is an enhancement of the Crafting Table and combines a chest and a crafting grid. Items placed on the grid will stay in the grid, even if you close the GUI. It also has an integrated inventory of 18 Slots, which it will utilize to draw resources from when crafting the items.
Any player can see the contents of the Project Table, including what is on the crafting area even while crafting.
If you look at the texture you can see 3 drawers and a cabinet. No doubt reffering to the fact that the table itself has an inventory space.