Hi,
Create an attribute of type wdy_boolean and bind the cell editor read only property of table columns to that attribute. Then in onAction Save, loop the table and set the attribute value to abap_true to make it disabled.
Check this document for reference: How to make selected row of table editable in Web Dynpro ABAP . In this I have demoed for single column, you can do the same for all columns.
Hope this helps u,
Regards,
Kiran