During last Sunday's session, Nictus the necromancer - who's stated in-character that his life goal is to live forever - has finally unlocked the Wizardry skill. He really, really wished to be able to resettle spell tablets, and now he finally can - but he's also hungry for more magic, I can read it in his eyes. My suggestion to the player was to start amassing spell tablets as his next pursuit, as the "wizard" Nictus only has one spell so far (Acridic Cloud).
Of course, should you have anything half-baked about creating that first spell-item for his grimoire or anything, now is a great time to send it my way and have it tested (with full understanding it's experimental, noncommittal, etc. etc. These players have been through my playtests, you know. Next session in 2 Sundays) - but that isn't the top reason I've rekindled this thread.
I wished to ask you specifically about spell tablets, instead. They're the main venue of accessing magic in the current draft, but without a bigger context (which I expect the future Grimoire chapter to provide, explicitly or implicitly) it's hard to gauge their social and economical role, the way we can instead infer a lot of setting information from the various lists of things in the rules.
You mentioned in your post that writing spell tablets is the kind of thing you expect wizards to be able to do "in the field" (not requiring a seclusium), and it looks like any literate person can effectively perform an act of wizardry using a spell tablet. Judging from the details "1" result on Examine treasure rolls, spell tablets are rarer and harder to acquire than mundane weapons and armor, but not overwhelmingly so. This suggests that wealthy people routinely have access to a spell or two, as curiosities or specialized tools. So far, I have equipped a few wealthy and resourceful NPCs with a spell, but never more than one, and last session I have put a spell tablet on display as a treasured possession - the way you would display a lucky find at an antique shop - but now I'm wondering whether I went overboard with it.
Also, what with spell tablets being tablets in a word which clearly has books, and even a notion of publishing as an industry? Feels like an interesting topic...