Hi hameed,
You can achieve this by adding item level permission on each excel files you uploaded on SharePoint.
Upload individual Excel files on SharePoint Doc Lib and give only owner to access it by selecting manage permissions on that particular document.
So others will not have access to that item.
You can show this excel sheets in EWA web part and only individual users can see their own data.
Warm Regards, Pratik Vyas | SharePoint Consultant | http://sharepointpratik.blogspot.com/