Specifies the output format of a report. The option has no effect when used with a command that does not generate reports, ...

Specifies the output format of a report.  The option has no effect when used
  with a command that does not generate reports, or a command that does not
  support this option.  The accepted values for  are:
    Table = Displays the report in a table.
    List = Displays the report in a list of name/value pairs.


    Examples:
     DISM.exe /Image:C:	est\offline /Format:Table /Get-Packages
     DISM.exe /Image:C:	est\offline /Format:List /Get-Features
     DISM.exe /Image:C:	est\offline /Format:Table /Get-Drivers
     DISM.exe /Image:C:	est\offline /Format:List /Get-Apps
     DISM.exe /Image:C:	est\offline /Format:Table /Get-AppPatches