I am using Entity Framework with C# to make a Silverlight application. I have written some stored procedures which perform database intensive operations and I need to call them
If you are using SQL Server, which I assume is the case, you can create use a table valued parameter to do what you wish. Using a table valued parameter prevents you from parsing an input parameter within the stored procedure and removes the threat of a SQL injection attack by eliminating the use of dynamic SQL.
Here is a great blog article that covers how to do what you wish to do.
Using Table-Valued Parameters in SQL Server 2008 and C#