After launching the Roku Media Player, you can select the format for viewing. If you want to see a "List View" format for all your media, then highlight/navigate to the folder "All" and press the * button.
From there, you select "Display Format" and enable "List" (you should see options for List or Grid).
There are various submenus for different settings before you get to the actual content, so just press this same * button to access the various settings.
This asterick * button is basically an "options" selector across the Roku platform.