PDF Document Page Size

I am trying to generate a PDF document but don't know how to control the Page size. As the printout is most likely A4, I would like to print it horizontally in order to fit my table in. The following is my code snippet. The first few rows of the table are the header.

        // ----------------------------------------------
        // Print Request Test Schedule Allocation
        // -----------------------------------------------
        private void cmdPrint_Click(object sender, EventArgs e)
        {
            FixedContentEditor editor;
            RadFixedDocument document;
            RadFixedPage page;

            document = new RadFixedDocument();
            page = document.Pages.AddPage();
            editor = new FixedContentEditor(page, new SimplePosition());           

            Table table = new Table();
            table.BorderCollapse = BorderCollapse.Separate;
            table.LayoutType = TableLayoutType.AutoFit;
            table.Margin = new System.Windows.Thickness(50);

            table = SetTableHeader(table);

            editor.DrawTable(table)

            TableRow tableRow;
            foreach (KeyValuePair<string, TDFCollection> tDFObject in T.FileList)
            {
                Block block = new Block();
                string name = tDFObject.Value.TDFName;
                string desc = tDFObject.Value.TDFDescription;
                string requester = tDFObject.Value.Requester;
                string duration = tDFObject.Value.Duration.ToString();

                tableRow = table.Rows.AddTableRow();
                tableRow.Cells.AddTableCell().PreferredWidth = 20;
                block = tableRow.Cells.AddTableCell().Blocks.AddBlock();
                block.TextProperties.FontSize = 12;
                block.InsertText(name);
                tableRow.Cells.AddTableCell().PreferredWidth = 30;
                block = tableRow.Cells.AddTableCell().Blocks.AddBlock();
                block.TextProperties.FontSize = 12;
                block.InsertText(desc);
                tableRow.Cells.AddTableCell().PreferredWidth = 35;
                block = tableRow.Cells.AddTableCell().Blocks.AddBlock();
                block.TextProperties.FontSize = 12;
                block.InsertText(requester);
                tableRow.Cells.AddTableCell().PreferredWidth = 5;
                block = tableRow.Cells.AddTableCell().Blocks.AddBlock();
                block.HorizontalAlignment = Telerik.Windows.Documents.Fixed.Model.Editing.Flow.HorizontalAlignment.Center;
                block.TextProperties.FontSize = 12;
                block.InsertText(duration);                
            }
            editor.DrawTable(table);

            int index = 0;
            string agendaFile = null;
            while (true)
            {
                index++;
                agendaFile = T.TEST_Scheduling + "Request Allocation" + " (" + index.ToString() + ").pdf";
                if (!File.Exists(agendaFile)) break;
            }

            PdfFormatProvider provider = new PdfFormatProvider();
            try
            {
                using (Stream output = File.OpenWrite(agendaFile))
                {
                    provider.Export(document, output);
                }
            }
            catch (Exception ex)
            {
                T.WriteLine("PDF Stream Write Exception : " + ex.Message);
                MessageBox.Show(ex.Message, "PDF Output Exception", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            MessageBox.Show("Test Schedule Allocation Requests PDF is created", "Print Test Allocation Requests", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

        // ---------------
        //  Set PDF Header
        // ---------------
        private Table SetTableHeader(Table table)
        {
            TableRow tableRow;
            tableRow = table.Rows.AddTableRow();
            tableRow.Cells.AddTableCell().PreferredWidth = 30;
            Block block = tableRow.Cells.AddTableCell().Blocks.AddBlock();
            block.TextProperties.FontSize= 14;
            block.GraphicProperties.FillColor = new RgbColor(0, 0, 139);
            block.InsertText("TEST SCHEDULING REQUESTS");         

            tableRow = table.Rows.AddTableRow();
            block = tableRow.Cells.AddTableCell().Blocks.AddBlock();
            block.TextProperties.FontSize = 12;
            block.InsertText(" ");

            tableRow = table.Rows.AddTableRow();
            tableRow.Cells.AddTableCell().PreferredWidth = 30;
            block.TextProperties.FontSize = 12;
            block = tableRow.Cells.AddTableCell().Blocks.AddBlock();           
            block.GraphicProperties.FillColor = new RgbColor(0, 0, 139);
            block.TextProperties.UnderlineColor = new RgbColor(0, 0, 139);
            block.InsertText("Test Definition");
            block.InsertLineBreak();

            tableRow.Cells.AddTableCell().PreferredWidth = 30;
            block = tableRow.Cells.AddTableCell().Blocks.AddBlock();
            block.TextProperties.FontSize = 12;
            block.GraphicProperties.FillColor = new RgbColor(0, 0, 139);
            block.TextProperties.UnderlineColor = new RgbColor(0, 0, 139);
            block.InsertText("Description");

            tableRow.Cells.AddTableCell().PreferredWidth = 35;
            block = tableRow.Cells.AddTableCell().Blocks.AddBlock();
            block.TextProperties.FontSize = 12;
            block.GraphicProperties.FillColor = new RgbColor(0, 0, 139);
            block.TextProperties.UnderlineColor = new RgbColor(0, 0, 139);
            block.InsertText("Requester");

            tableRow.Cells.AddTableCell().PreferredWidth = 5;
            block = tableRow.Cells.AddTableCell().Blocks.AddBlock();
            block.TextProperties.FontSize = 12;
            block.GraphicProperties.FillColor = new RgbColor(0, 0, 139);
            block.TextProperties.UnderlineColor = new RgbColor(0, 0, 139);
            block.InsertText("Duration");

            block = tableRow.Cells.AddTableCell().Blocks.AddBlock();
            block.TextProperties.FontSize = 12;
            block.InsertText("    ");

            return table;
        }   
    }