I asked this elsewhere but the comments I received were not helpful.

The tablet chaos token says to ignore all bonuses to your skill. I am not sure what is defined as a bonus. I assumed that it was any positive modifier. Regardless of the source. Do I have this right?

Ignore all positive modifiers would be my interpretation also. I wouldn’t consider changing your base skill, e.g. by using Duke, The Red Gloved Man or Trial by Fire, to be a bonus for the purposes of the Tablet token’s effect. However, I don’t think bonus is explicitly defined anywhere in the rules so I can’t guarantee this is correct.