Pass DataTable To DAL

I would like to pass a datatable to the DataAccessLayer from aspx.cs page. DAL is another project and CountryDal is a class file in it. Unable to do it using the session object. What is the proper way to acheive this.

ASPX.CS

private countryDAL objDAL = new CountryDAL();

protected void btnSave_Click(object sender, EventArgs e)
{
  //code...
  Session["tbl"] = dt;    //dt is a datatable with some data
  objDAL.SaveTable();
}

DAL

public void SaveTable()
{
  DataTable dtSave = (DataTable)Session["tbl"];

  //code.....
}