The flora in the world around you seem to have vast untapped power. What better way to access that than mashing them into a pulp?
Of course, to mash the aforementioned plants into a pulp, you're going to need something to mash with. This pestle, fashioned out of a smooth white stone, should do the task nicely.
Using the mortar and pestle is quite simple. Detailed in this tablet are many recipes for different spells. You will need all of these ingredients, as well as a particular base ingredient. To create the most basic possible spell, simply place in the spell's recipe, as well as an old root. This will allow for a spell with no modifiers.