"In the Spreadsheet question type, it’s not possible to omit the row names. However, you can reduce the row width by going to the question settings and selecting the appropriate value from the “Question Width (in %)” dropdown. Adjusting this setting will help expand the column space by reducing the row width.
To reduce the row width :
Survey >> Edit >> Spreadsheet Question >> Settings >> "Question Wdth".
Screenshot for reference: https://app.screencast.com/F7YIlyh7MvloD"