Magician = Mage. Magician (CoM) has Magician's Versatility so ability to know up to 40 spells - note that Elemental Ball, Elemental Bolt, etc., come in 4 spell versions. Other Mage variant professions may know up to 30 spells. Clerics may know 20 spells. Harpers, Rangers, Warrior Mages may know 15 spells.
Something Wicked, Something Wondrous will introduce a talent which allows characters to increase their spell repertoire by 5 spells.
Best wishes,
Nicholas