A family of Microsoft relational database management systems designed for ease of use.
Ok, That paragraph outlines what needs to be done. It tells you that an Append query would be used to populate the table.
To add the table without a join, just Add it from the table pane but don't join it to the student table. Like I said this is a step by step process and you should be concentrating on getting the first step right before thinking about the next steps. Once you get the first step right the next steps will become clearer. The first step is creating a query that returns a record for each student in the center for each course. Have you done that? If not what is not working? Show me the SQL.
"This is taking more time than I expected. "
Then your expectations were off. Developing an Access database is not a simple task, especially for the novice. There is a pretty steep learning curve for Access. While an experienced developer could churn out your app in a couple of days, it may take weeks for the inexperienced.