"You are not doing this at the Taipei table," says Cai Baihan absolutely flatly, when she shows up to breakfast.

"Understood, Bai-xiong," she says, scans an adjacent one that nobody wants to sit at because it's on a (totally unoccupied, per her scan-spell) vent, and sets up there.

Then she unfolds the sign.

In VERY LARGE CHARACTERS, and in Mandarin, it says:

HOMEWORK & SPELLS

MANDARIN, ENGLISH, TAIWANESE, HINDU, CANTONESE, GERMAN, LATIN, GREEK, JAPANESE, CLASICAL CHINESE, ROMANCE LANGUAGES

HOMEWORK: ANY CLASS, ALL YEARS

WE ACCEPT: MANA, ARTIFICE, POTIONS, SPELLS

And, what is not going to get her kicked out unless she screws this up badly:

C OR HIGHER OR 200% REFUND, WITH PROOF OF PURCHASE.

SPELLS: LOW-MANA, GENERAL-PURPOSE, WE WILL TRADE.

Then she unfolds another one, in English. And almost a dozen smaller ones in almost a dozen other languages, making sure to take up as much space as possible so it looks like Cai Baihan was motivated by a desire for her not to eat his entire table, instead of a doomed hope of being outside the explosion radius. 

Jinye has, of course, all the homework (including an astonishing amount of extra credit) from all of her classes so far calmly stacked on her desk in front of the signs, A grades clearly marked, including calculus and linear algebra.

Sometimes, insanity is the only safe move.