Is there a way to implement the workflow and user roles for Content authors to see their own items only in workbox not from other authors.
No, there is not. Sitecore's security (of which Workflow is an integral part) is Role-based, not individual based. The ability to "see" and "act" on an Item in the workbox is determined by the following:
- Does the User have "Write" rights to the Item in question?
- Does the User have "Workflow Write" rights to the Item's current Workflow State?
if either of these are false, the given Item will not show up in the User's Workbox. Since most of your users probably can answer "yes" to both of these questions, they will all be able to see the Item in the Workbox.
Note that Item Locking doesn't affect visibility either, it just prevents the user from actually editing the Item once they select it in the Workbox.