I think you are looking for restricting access and available actions for anonymous users
Please see the above link for configuring module security. You can add security based on user roles to your pages accessible from datagrid (like add, edit etc). Also you can set entity access rules which defines who can create, read, write or delete objects of an entity.
If further you want to show your rows looking greyish/disabled, you may define a custom css class and add some css for it to change row color and mouse pointer when hovering it.