The Tablet of Destiny is unique from other accessories, as it has no direct use. Holding this item only has the functionality of changing its own journal entry to a prophecy relating to the Ushabti in 6-2. The prophecy includes three descriptors relating to a specific Ushabti, formatted as:
"A (descriptor) servant of (material) marked by the (symbol) will open the door for the Aspirant."
Taking the Ushabti fitting this description to 6-3 will make it start ringing, then shortly thereafter burst into the Qilin.