We have the following page structure:

• Page 1
  • Page 1.1
  • Page 1.2
  • Page 1.3
• Page 2
  • Page 2.1
  • Page 2.2
  • Page 2.3
• etc.

In this structure, the parent pages (Page 1, Page 2, etc.) usually do not contain any content. Instead of just linking them automatically to the first subpage (click Page 1 --> Page 1.1, click Page 2 --> Page 2.1 etc), we would like to have a summary of the subpages, e.g. Page 1 consist of the title and description of Page 1.1, Page 1.2 and Page 1.3.

Can this be automatically be done by DNN? Actually every page has a title and description, so can DNN automatically create such summary?

This may not quite do what you're hoping but it could be helpful while you determine a better solution...

   Free module to display links to child pages under a designated parent page
   http://www.snowcovered.com/Snowcovered2/DotNetNuke/Modules/Child-Page-List-20-free/id/12399
 

You'll need to manually add the module to each parent page. 
-mamlin