In initial descriptions, derro savants knew 1d4+5 of the following spells:
affect normal fires, anti-magic shell, blink, cloudkill, ESP hypnotic pattern, ice storm, invisibility, levitate, light, lightning bolt, minor creation, paralyzation, repulsion, shadow magic, spider climb, ventriloquism, wall of fog, wall of force.
Breaking this down into PFRPG schools, yields the following list:
Abjuration: anti-magic shell*, repulsion
Conjuration: cloudkill, fog cloud
Divination: can use comprehend languages and read magic at will
Enchantment: ESP**, paralyzation***
Evocation: ice storm, light, lightning bolt, wall of force.
Illusion: hypnotic pattern, invisibility, shadow magic****, ventriloquism
Transmutation: affect normal fires*****, blink, levitate, spider climb
*as PFRPG anti-magic field
** as PFRPG detect thoughts
*** no direct PFRPG correlate, consider hold person
**** as PFRPG shadow evocation
**** no direct PFRPG correlate
And classified by level (as per Sorcerer class):
2nd: detect thoughts, fog cloud, hypnotic pattern, invisibility, levitate, spider climb
3rd: blink, hold person, lightning bolt
4th: ice storm
5th: cloudkill, shadow evocation, wall of force
6th: anti-magic field, repulsion
So in summary: spells involving misdirection and allowing capture of prisoners are favoured, with some conjuration and evocation effects whereas necromancy appears to be passed over completely.
Note: these are all core spells, excluding spells from later supplements