It is strongly recommended that you Duplicate the out of the box report instead of making changes to the original. You can then customize it as needed. We now offer an online Adobe Campaign 6.1.1: Reporting class that teaches you how to create custom reports using the same Report Builder tool that is used for the out-of-the-box reports. I recommend that you go through this class to learn how to parameterize the report. The report Page can have multiple tables and charts as needed, there is not a restriction on this, just add them in the Page activity.
To access the online learning, go to solutionpartners.adobe.com. Here is a link to the course itself: Saba