Hey Troy, thanks for reaching out! You can delete rows in mass by selecting the first row you'd like to delete on the left hand side of the screen, scrolling down to the last row you'd like to delete, hold shift, and click on the small box on the left hand side of the cell. Then you can right click and select "Delete x# of rows".
Recorded a quick video showing the process. Hope this helps! Let me know if you have any other questions. :)