How to Enter New Tasks in the Outlook 2013 Tasks Module
Type the name of the task in the Subject box.
Use a subject that will help you remember what the task is. The main reason to create a task is to help you remember to do the task.
You can finish at this point by clicking the Save & Close button or pressing Alt+S if you want to add only the name of the task to your list. If you want to note a due date, start date, reminders, and so on, you have more to do. All the rest of the steps are optional; you can skip the ones that don’t interest you.