Can I delete columns/headings in Open Activities on Contacts Details Page?

Can I delete columns/headings in Open Activities on Contacts Details Page?

How do I delete columns on the Open Activities section of the Contacts Details Page. I've figured out how to modify many things but can't seem to find this.  Right now it has Subject/Activity Type/Status/Date Due/Start Date time/End Date time/Owner Name.  I would like to eliminate the columns for Start Date Time and End Date time as I don't use those.  Thanks for your help!