While working with Microsoft Office SharePoint server 2007 datasheet view will help end users to add or edit the SharePoint list data using Excel like view.
But some time if you found a message at the bottom of the datasheet view as ‘This view is read-only.’ (As shown in below image) and you are not able to add, delete or update the record using the datasheet view.
To resolve this you need to go to the ‘List setting’ section of that same list and select ‘Versioning Settings’ from General Settings section.(As shown in below image)
Now go to ‘Content Approval’ section and set ‘Require content approval for submitted items?’ to No.(As shown in below image)