The course completion report table tends to overflow the page if there are a lot of criteria to be met. Overflow: auto doesn't fix this. If you check the activity completion report page, you will see that the table is within a div that can be set to overflow:auto with great effect. Can the course completion report page please mirror the activity completion report page? Also, if you check out the styles of the table, they are also much better in the activity completion report.
On a side note: any possible chance of being able to choose between ticks and crosses and having specific grading scales within? (C for competent, NYC for Not Yet Competent, that kind of thing - preferably linked to whatever scale you put in for grading scales).