Answer
No, personal geodatabases are not multiuser databases. As a result of this, when editing any element of the personal geodatabase, a lock is placed on it. All items in the geodatabase are locked against editing, until released by the user currently editing.
If multiuser access and editing is required, use an ArcSDE geodatabase.
For additional information regarding the multiuser geodatabase, refer to the ArcGIS Web help topics under Geodatabases > Multiuser.