There are two different methods of viewing a database in LibreOffice.
Choose File - Open to open the database file.
The database file gives you full access to tables, queries, reports, and forms. You can edit the structure of your tables and change the contents of the data records.
Choose View - Data source to view the registered databases.
The data source view can be used to drag-and-drop table fields from registered databases into your documents and to produce mail merges.