#### Bug, feature request, or proposal: How to display data table with nested array in material table. #### What is the expected behavior? #### What is the current behavior? #### What are the steps to reproduce? Providing a StackBlitz reproduction is the *best* way to share your issue. <br/> StackBlitz starter: https://goo.gl/wwnhMV<br/> #### What is the use-case or motivation for changing an existing behavior? #### Which versions of Angular, Material, OS, TypeScript, browsers are affected? #### Is there anything else we should know?