As of the time and date indicated, this is the total enrollment, and overall course enrollment limit for this section.
Some jointly-offered courses are subject to a joint limit (not shown) which is why a course may be marked as closed even though it appears to have fewer students enrolled than the section limit.
An "E" after the limit means this is an estimated enrollment rather than a limit. A course with an estimated enrollment closes when the enrollment equals the room capacity or when the estimated enrollment limit is reached if there is no room capacity indicated.
Enrollment is not allowed beyond 115% of the official room capacity of the smallest room assigned to the section.