When a container consists of thousands of entries, its opening takes too much time before all the subentries are displayed.
Generally speaking, getting a thousand entries or more is not a fast operation because of the amount of data to be transferred. Besides, LDAP Administrator and LDAP Browser have certain tricks to ensure a better appearance in process of the smaller and mid-sized directory browsing. But if you surf through heavily stuffed LDAP directories, such tricks can slow the overall application performance down considerably.
To improve on the performance of LDAP Administrator/LDAP Browser, open the Tools menu and choose the Options menu item. In the dialog displayed click the Interface tab. Uncheck the Fetch subentries upon item selection and the Force to display the entry fetched last checkboxes featured thereon.