Changing Data 
By default, you cannot change data in the list. However, your application can be set up so that you can still make changes.
Prerequisites
Your list is set up to be editable.
Features
If your application permits the data to be changed, the following changes are possible:
Inserting or deleting rows at a specific position
For more information: Inserting, Appending,and Deleting Rows
Changing single values
For more information: Changing Single Values