Preface : This is not me being unhappy at the current Tome rewards that are given out for quests and occasionally as DM event rewards. This is just a suggestion to improve how the system feels
Currently there have been two types of XP tome I have come across
Minor XP tome : With my current XP boost of a full small house and an extra 5% boost = 600XP to one skill of your choice
Regular XP tome : As above but around 1150XP to one skill of my choice
At the current skill level that most of my skills are at, being around 30-40 range for the main targets, Heavy armour, Twohanded, Weapon/Armourcrafting.
Its like a very small drop in the bucket, Most enemies give half the amount of a regular XP tome, and I can craft 1-2 items and get the same XP from these rewards!
So the suggestion I have for these, is instead of a flat number as that falls of incredibly hard, and would need around 40ish XP tomes to level some skills once you start getting to higher tiers. (And I realise they are meant to be supplementary, not a main way to level)
Is have them reward a % of whatever skill you choose’s, Level in progress
Minor tomes : 20-33% increase towards the next level of the skill you choose
Regular Tomes: 50-66% increase towards the next level of the skill you choose
Major Tomes : 80-100% (A whole level) Increase to the next level of the skill you choose
I believe changing the static XP rewards to a % would be more rewarding in most cases. The static XP is better for leveling low-skills (But so is killing 1-2 enemies) while a %XP reward would be better for high-level skills.