no there isn't , it's basically a history of what you played, you can't change history
I just wish it gave you the option to not display XBLA trials (seems silly that game demos don't show up but XBLA trials do)
You CAN however, set it so others cannot view your games list.
The option is somwhere in the Xbox dashboard with the rest of your user settings, probably under "privacy" I've never looked for it but I know others who have used it.
