Right-clicking the smithing or fletching table whilst in spectator mode opens the crafting table GUI for a split second.
Spectators can open all blocks with guis except for ender chests, command blocks and structure blocks.
Right-cliking on smithing table and fletching table in sectator mode show crafting table GUI
Crafting GUI opens in spectator mode when clicking on certain blocks.
Right-clicking smithing table whilist spectator mode