You can print a collection of several reports and generate a table of contents if the collection is large enough to warrant it.
When you right-click in the Reports portlet, and select New Group, the Group Reports editor appears. It has the following fields and panels:
Name -- Identify the report group.
Title -- Optionally provide a title.
Subtitle -- Optionally provide a subtitle.
Generate Table of Contents -- Check this box to generate a table of contents listing the reports grouped together by this group.
Click Add Report (the green plus) to open a selector with the available reports. Select reports to appear in this group. Each report has an entry in the table of contents, if you elect to generate that.