History of Tome of Want

The Tome of Want is an inventory accessory from Episode: Heresy that lets Guardians target-farm rewards by socketing Scriptures and powering rituals.

Unlocking

TheGamer says it unlocks at Rank 3 with the Shaping Slab vendor and is opened from the inventory tab where tonics are consumed.

How it works

• Socket Scriptures into its slots: category Scriptures set the reward type (episodic weapons or armor, reprised weapons, world drops, resources) and modifier (Crumbling) Scriptures refine it, such as to a weapon type. Destinypedia's primer also names Amorphous Scriptures, Exotic-focused ones.
• Infuse rituals with Essence of Desire. Progress builds from activities such as The Nether, Vanguard Ops and the Crucible, most from Heresy content. Full rituals grant rewards and consume the Scriptures.
• Tome Engravings unlock over time and add effects to Artifact perks while a ritual is active.
• Weapons can also be focused with Scriptures; e.g. Adamantite.

Sources differ on scripture naming (Rare or Crumbling vs category or modifier) and details of the third slot; check in game.