This functionality exists for some note types but not for others.

For constituent notes, it's possible to see the author a constituent notepad by going to the constituent record and then, in the "Notes and actions" panel, clicking the total number of notes. This takes you to a list of notes, with the note author available as a column.

For gift notes, the note's author is shown next to the notepad date when looking at the gift record.

It's disappointing that this functionality doesn't exist for other notepads, such as action notepads, and that there is no consistency.