One of the fundamental design criteria behind the ODBC standard is the ability to run ad-hoc queries. In order to do this, the ODBC driver needs to access certain system tables. It is therefore impossible to block access to these tables if you are connecting via ODBC - if you were successful in blocking access to the tables then ODBC would no longer work. See http://msdn.microsoft.com/en-us/library/ms712628(VS.85).aspx for details of the Microsoft ODBC driver.

However, some ODBC driver vendors recognise that allowing the end user to see the system catalog views can cause problems, and have an option in the connection string or a registry option to prevent direct access by user SQL to the system tables. If this facility exists in the Microsoft ODBC driver, you may be able to force this option in your MS-Access connection - check the documentation to find more on this.

If all else fails, you can try DENY access to the sysetm tables to the Public role, but this may cause unwanted side effects that stop things you need from working.