Tablet

A Tablet is used with the Parcel Pyxis in the Land of Wind and Shade in order to request an item. John Egbert finds several carved Tablets in the introduction to Act 4, as well as a single uncarved one (which he may presumably use in order to gain an item for himself).

Oddly enough, many of the Tablets seem to request items that in fact belong to John's Dad; for example, his pipe, or his hat.