Is there a word for the object of a dilettante?

Solution 1:

I suggest dabblings, a word that you approach in your question, and one that fits your specification well.

dabbling noun

a superficial or intermittent interest, investigation, or experiment

“his dabblings in philosophy and art”

Merriam Webster

Among my own dabblings is an interest in English language and usage.

Solution 2:

My professional skills include writing a balance sheet, taxes, and forensic auditing. Astronomy and metaphysics are among my amateur interests.

Solution 3:

Dilettante is a bit of a pejorative (as you noted), so you probably don't want to invoke that.

How about avocation?

1 : a subordinate occupation pursued in addition to one's vocation especially for enjoyment : HOBBY
_{Source: Merriam-Webster avocation}

Example: My professional expertise includes balance sheet writing, tax preparation, and forensic auditing. Among my avocational pursuits are astronomy and metaphysics.

Or maybe just: My professional expertise includes balance sheet writing, tax preparation, and forensic auditing. In my spare time I enjoy studying astronomy and metaphysics.

Solution 4:

What a dilettante does is their "pastime". ("an activity that someone does regularly for enjoyment rather than work; a hobby" -- from Oxford Languages)

I don't know of a single word for what you're actually requesting, though. Usually it would be a phrase or implied...perhaps in an "About the Author" (or artist, or developer, etc.) page. "She earned her degree in financial accounting at Made Up University; but has happily not used this skill at all as a writer of technical manuals."

Solution 5:

A diversion can be ‘A hobby; an activity that distracts the mind.’ (Wiktionary)

(As @sameagol mentioned, the related French word ‘divertissement’, meaning an entertaining diversion, is also used in English, though I think very rarely.)