Unfortunately and somewhat inexplicably, it's not possible to set the Memo column to appear in the Bills & Income screen.
There is an existing Idea thread (request for feature/enhancement) for adding the Memo field to that screen; you should
click on this link to visit that thread and add your vote for it (in the yellow box under the first post). "
I never got round to voting, and I'm disappointed with myself for that.
Anyway, it looks like that a partial fix has been introduced.
I've just noticed in the Bills & Income window, Edit all Instances of a transaction, you see "addTags/memo/action".
I've just used it to add a note/memo to one of my recurring debits.
However, I still would have preferred a column where we can post a comment that can always be seen/visible.
QuickPeter