miscellanist; miscellaneous writer
A writer who produces essays, short pieces, or varied informal writings rather than long-form works. The term is somewhat literary and not an everyday word.
He is known more as a miscellanist than as a novelist.
Compound of 雑文 (miscellaneous writings) and 家 (person who does something professionally). The exact historical derivation is uncertain, but the term follows a common pattern for occupational nouns.