Let me see if I can help.
1. On the assignments list, you will notice a little "-" button under each of the column headings. If you click that, it will hide columns. You can hide things like the user picture in order to better see what is on the right.
2. While I'm discussing the header row, keep in mind that the titles over each row are clickable and that will order the list according to that column. For example, you can order your student roster by first name if you click on the "First name" header.
3. At the bottom of the page your can filter out all records except those that need grading. That may help.
4. I also sometimes adjust the font size on the browser (make the font smaller) so I can see more of the grade list. For example, on Firefox, I can tap "Ctrl -" (that is Control and the Minus key) to zoom out and see more of the roster. When I'm done, I "Ctrl +" (Control and the Plus key) to zoom back to normal; or use "Ctrl 0" (Control Zero) to go back to normal size.
Hopefully, some of these ideas will help.
Cochise College, Arizona, US