I thought I already responded to this but maybe it was a different forum. You need to change your audit entry in the Principal Name column from dbo to...

Take a look at this logon event generated by SQL 2008 Audit and then refined by LOGbinder (www.logbinder.com). Does that give you what you need? http://www.ultimatewindowssecurity.com/securitylog/encyclopedia/event.aspx?eventid=24001

I don't think you enabled the right action groups. If you want to audit whenever create, alter or drop is executed on a schema object such as a table,...

This would make it easier to roll back to your current audit policy, if any. there's also a free audit policy wizard at http://www.logbinder.com/products/logbindersql/resources/wizard.aspx