Add date column
We often display an activity set whose children have the same title but occur on a different date. How is a user supposed to know which one to enroll in? Could the start date be added to the Register table? It’s not best practice to add dates to the title of an event.
Move the enroll checkbox to the far left.
Checkboxes are commonly shown at the left. People miss the ones on the right, especially since the table header has no value for that column. There are just light gray boxes hanging in space. So easy to miss!
Remove the status graphic
That progress circle looks like a radio button waiting to be clicked. Why have it? Why not just use text?