My advice would be to make each note a new record. By appending, you have no way of associating added notes with the entry date, the db user who input the notes, thus such details will not be searchable (i.e. notes between or on a date / by a user). You will have to use code to append to existing notes, or just let people click into the field and start typing. That's a good way to lose everything that was entered before, which means the entire notes history as well.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.