It sounds like the issue you're facing is one of clutter. You mentioned in a prior comment that your users may need to "compare notes" across multiple users at the same time. So why not do this:
- Add a checkbox to the far left column of the table (in each row)
- Limit visible notes to ~100 characters or so
- When a user is "selected" (ie. their checkbox is checked), expand their notes section to display the entirety of the note
This allows you to limit the amount of clutter you have on the screen, have at least a glimpse of each user's notes, and expand multiple note sections at once.
Other components you may want to consider, depending on how much data you have:
- Card Containers
- Rows that can expand to show a more detailed view
It's best you avoid relying on hover/tooltips.
Update - Based on your update ;)
Generally, it is "dangerous" to manage note fields this way. Versioning or logging notes is preferred, as it preserves original text, can add context/history, etc.
If you don't care about any of that, you really have two different behaviors at your disposal to initiate a save:
- When a user clicks out of a row, or moves to a different user, the user auto-updates/saves
- As soon as any changes take place, add a "save/update" button to the screen (one that should be their normally, but in a disabled state). The user should click this button to initiate a save. (May be worth have a "save all" button at the top/bottom of the grid as well)
In both of these instances, there should be some sort of indication that a save is taking place when a save is initiated.