The Task list has the options to delete all the tasks as well as to delete the completed tasks.
Option to delete all the tasks can be found in the menu options of the Task list. Clicking the ‘Delete All‘ option will prompt a confirmation window. Confirming delete will delete the tasks permanently.
This option can be found in the Task list menu options. Clicking this deletes all the tasks whose status has been updated to completed. This is a handy tool to clean up from the list, the tasks that are completed and you might not need.