If you have a course which has a lot of assignments, you can jump to an assignment to other assignment by using a table view of all assignments on the course.
Assignment1
Assignment2
Assignment3
...
Assignment10
If you want to check all assignments from Assignment1 to Assignment10, you will check assignments from 1 to 10 in sequence.
The patch allows you to jump to previous one or next one from current assignment easily by only pushing [Previous assignment] and [Next assignment] button on Quick grading screen!
Please see Tracker issue MDL-20401.