Why is my report getting spread to 4 pages when it can easily fit on one

Warning[] warnings;
            string[] streamids;
            string mimeType;
            string encoding;
            string extension;
            byte[] bytes =ReportViewer1.LocalReport.Render("PDF", null, out mimeType,
            out encoding, out extension, out streamids, out warnings); //converting into pdf
            MemoryStream s = new MemoryStream(bytes);
            //s.Seek(0, SeekOrigin.Begin);
            Attachment att = new Attachment(s, file);
            SmtpClient smtp = new SmtpClient("pod51014.outlook.com");
            MailMessage msg = new MailMessage();
            msg.Subject = "Invoice Report";
            msg.From = new MailAddress ("209@dut4life.ac.za");
            msg.To.Add(get_Email());
            msg.Attachments.Add(att);
            smtp.DeliveryMethod = SmtpDeliveryMethod.Network;
            smtp.EnableSsl = true;
            smtp.Credentials = new System.Net.NetworkCredential("209@dut4life.ac.za", "Dut920925");
            smtp.Port = 587;
            smtp.Send(msg);