All homeworks are out of 100 points. Q are quiz grades. Q1 refers to Quiz 1. Q2 refers to Quiz 2, and so forth. All quizzes are out of 10 points.
E are exam grades.
E1 refers to the first midterm. This grade was out of 100 points. Your grade currently consists of homeworks, quizzes and exams. At the end of the semester, your grades will be averaged from the remaining quizzes. If anything, this is the column that is likely to have the most mistakes.