To work with mdb file, open the OpenOffice.org-base select connect to an existing database, select Microsoft Access.
browse the mdb file and you need to save a odb file that will enable you to view the tables,query etc on it.
To copy the content of a table in OpenOffice.org Calc
go to View–> Data Sources
right click in the left pannel of in the database view option, click on the “Registered databases”, click “New” and locate your created odb file.
Click on the database you want to copy. Select the Queries/Tables and copy the content by righ click on the query/table name.
Paste in the OpenOffice.org-Calc. Now you can save in ods, and also save as in different formats.