One of the most basic operations in Workfront is to make changes to objects in a list. Virtually all object lists are in-line editable.
Hovering over selected (double clicked) rows in a list shows a slight shading. While in selection mode, click in a field to enable that field (and the entire row) for editing. Use the keyboard or mouse to navigate within the fields, from field to field, and row to row.
Users can only edit fields andfor which they have access. Any calculated fields or cross-object fields are not editable. (For example: the project owner on a list of tasks could not be edited. You would have to edit that in a project list.)