House Rules
Ancient Tablet
Wonderous Item, Upgradable: uncommon(+1) (requires attunement by an artificer)
This compact tablet made of unusual materials is about eight inches long, four inches wide, and half an inch thick, with an uneven, sturdily-framed structure with a design that allows it to be held easily in hand or to be fastened to a properly-designed bracer. It functions as an arcane focus for Artificer spells, adding a +1 to spell attack rolls and spell DC, and it can serve as the arcane firearm for an Artillerist .
As an action, you can focus on the tool to channel your creative forces. Choose a cantrip that you don't know from any class list. For 8 hours, you can cast that cantrip, and it counts as an artificer cantrip for you. Once this property is used, it can't be used again until the next dawn.
The tablet can project fields of faintly glowing force, capable of replicating the form and function of artisans' tools which you are proficient with, though these temporary tools only grant half of your proficiency bonus on relevant checks (rounded up).
The tablet can also interact with the use of the magical tinkering class feature, having access to an internal ability to remember and manifest visual displays and sounds. It can save and capture images (including maps drawn with cartography tools, or images of something the user can see), longer segments of text, audio recordings, or even brief snippets of visual and audio data. The device surely has some storage limit, but can hold at least as much written information as a large spellbook. These 'magical tinkering' effects don't count against the number of magical tinkering effects that can be applied to other items. Sifting through the information can be done as an action or bonus action by the attuned user of the tablet.
The device has several discovered but inactive functions, including a translation function, an ability to interface with other devices such as clockwork familiars, and an active map feature. Technical upgrades can potentially unlock or improve this tablet's function. Other functions may either be undiscovered or potentially installed into the device by a skilled owner.