To manage your personal information, the familiar four PIM (Personal Information Managers) are Calendar, Contacts, Reminders, and Notes.
Or, Date Book, Address Book, To Do, and Notes, very well defined since the palm/pilot days.
You know an appointment goes into Calendar. Contact info should be in Contacts. To-do items in Reminders (or maybe Things). All others, in Notes?
But what about all those pieces of data that is not an event, not a contact, not a to-do, yet have a bit more structure than just a free-form note?
Put it in you Kase.