Hi,
SQLyog's Import External Data requires access to the system tables of the Microsoft Access database for the purpose of reverse-engineering. By default, read access to the system tables of an Access database is restricted for external applications. The procedure to enable the read access depends on the MS-Office/Access version. But in every case you must first un-hide the system tables and next change some of their properties. This procedure is explained here: http://www.webyog.com/en/whitepapers/Preparing_Access__Migration.pdf
Please follow the steps as mentioned in the above Preparing_Access__Migration.pdf file and you will be able to import properly.
Thanks and Regards,
Ashwin A