fapDaddy's answer using a macro pointed me in the right direction.
Here's precisely what worked for me.
Place the cursor after the first data item.
Click 'Macro > Start Recording' in the menu.
Type this sequence: Comma, Space, Delete, End.
Click 'Macro > Stop recording' in the menu.
Click 'Macro > Run a Macro Multiple Times...' in the menu.
Click 'Run until the end of file' and click 'Run'.
Remove any trailing characters.
Done!