Technically, the Character Profile Window is not actually part of your comic collection, but it's available if your interested.
If you read Wizard magazine, you'll notice that recently they've been including a Character Profile at the end of each issue (Superman, Hulk, Wolverine - obviously starting with some of the most famous names).
That was actually the inspiration for this portion of Realms. The intent was to give you a place to track information about characters. This information can span many issues (in fact hundreds or thousands, if youre talking about a character who has been around a while).
This might also be useful for tracking clues about unknown or mysterious characters (like Onslaught in the recent Marvel books) who are destined to be a significant presence in their respective universes.
You can track the following information about a character: