export option in libreoffice database is not working

I have MSaccess accdb file and able to connect it using base. It has 90+ tables. The option file->export is disabled. There is no way of exporting the db. Is there a way of exporting all the tables in one go ?

To export data from Base you need to use Calc, or the SQL command window.

Using Calc

I refer you to this documentation: Importing and Exporting Data in Base.

Generally the procedure is to copy each table to an individual spreadsheet. Finally you export each spreadsheet sheet to a CSV file.

Using SQL command

From the Tools menu choose Tools->SQL.
In the SQL command window that opens, enter the command SCRIPT followed by a path to the destination file, to store the export in, such as /tmp/export.sql. Make sure the path exists.
This will result in dumping the entire database to an .sql file for importing into other database software, or back into another Base document.

Reference: Can anyone help me convert my ODB file to SQL?