To rename what is displayed as a name for Tasks in Google follow the steps outlined below. Please note that you cannot create, rename or delete task lists in Google Calendar. 

1. From your email view, if the side bar with Calendar, Keep, and Tasks is not open, click the < sign on the right bottom portion of your screen.
   
2. Click Tasks from the side bar.
   
3. Click the vertical three dots next to Add a task, then click Rename list.