Asset Manager has the ability to enable editing in a number of ways, this quick overview will help get you familiar with those capabilities.
Bulk Update - In Search and Filter view you can choose to bulk update attributes for all the records currently in the grid
Edit Individual Record - In Details View you can edit the attributes of an individual record
Create Related - In Details View, you can view a list of related records as well as create a new related record
Edit/Delete Related - In Details View, you can view the details of a related record as well as edit or delete a related record