How to get data with table formate in pdf

my code is

StringBuilder sb = new StringBuilder();    
        sb.Append(""); 
            sb.Append("");         

 sb.Append(""); 
            foreach (DataGridViewRow row in dgv.Rows)   
          {               
  foreach (DataGridViewCell cell in row.Cells) 
                {            
         sb.AppendFormat("");   
                  sb.AppendFormat("");     
                sb.AppendFormat("");        
         }                              }             sb.Append("
          
"); 
                        sb.Append(cell.Value); 
                    sb.AppendFormat("
");             return sb.ToString();