If you follow the bouncing ball from the notes/index.php page you end up at the function note_list() in notes/lib.php. There is a call to $DB->get_records_select() on around line 62 (exactly 62 in my code, but your version might be different) and this queries the table <prefix>_post.
So the table in your environment is likely to be mdl_post if you're using the standard table prefix.
Have a look in that table and see if what you're after is there.