Trying to change the name of the “Body” section inside a For Each Row in Data Table activity by double clicking does nothing, as opposite to any other activity title. Inconsistently enough, if you right-click on the “Body” text, it displays the same context menu as in the title of an activity, giving you the option to rename it.
EDIT: I just realized that context menu is for the activity itself, not for the “body” part. Anyway… you can’t rename the “Body”.