Datatable to Notepad with value repeat on each page with line break

@Amit kumar Yadava , Welcome to Microsoft Q&A， you could try to group by your datatable and use list of string to write all the lines to txt file.

Here is a code example you could refer to.

Dim dt As DataTable = New DataTable()  
    dt.Columns.Add("Id", GetType(Int32))  
    dt.Columns.Add("Item", GetType(String))  
    dt.Columns.Add("Qty", GetType(Int32))  
    dt.Columns.Add("Date", GetType(DateTime))  
    dt.Rows.Add(101, "Pen", 5, "2021-10-05")  
    dt.Rows.Add(102, "Bag", 10, "2021-09-06")  
    dt.Rows.Add(101, "Copy", 2, "2021-01-05")  
    dt.Rows.Add(101, "Glue", 10, "2021-03-05")  
    dt.Rows.Add(102, "Conver", 5, "2021-10-02")  
    dt.Rows.Add(101, "Cover", 10, "2021-10-01")  
    Dim result = dt.AsEnumerable().GroupBy(Function(row) row.Field(Of Int32)("Id"))  
    Dim count As Int32 = 1  
    Dim arrcount As Int32  
    Dim sumaccount As Int32  
    Dim list As New List(Of String)  
    For Each grp In result  
        Dim str As String  
        str = String.Format("                               Page{0}", count)  
        list.Add(str)  
        str = String.Format("Item Issued For Customer :{0}", grp.Key)  
        list.Add(str)  
        list.Add("--------------------------------------------------")  
        str = String.Format("{0} {1} {2} {3}", dt.Columns(0).ColumnName, dt.Columns(1).ColumnName, dt.Columns(2).ColumnName, dt.Columns(3).ColumnName)  
        list.Add(str)  
        list.Add("--------------------------------------------------")  
        Dim arr = grp.Select(Function(row) row.ItemArray)  
        For Each line In arr  
            list.Add(line(0).ToString() + " " + line(1).ToString() + " " + line(2).ToString() + " " + DateTime.Parse(line(3).ToString()).ToShortDateString())  
        Next  
        list.Add("--------------------------------------------------")  
        Dim sum As Int32 = grp.Sum(Function(row) row.Field(Of Int32)("Qty"))  
        Dim final As String  
        final = String.Format("Total {0} {1}", arr.Count, sum)  
        list.Add(final)  
        list.Add("--------------------------------------------------")  
        arrcount = arr.Count + arrcount  
        sumaccount = sum + sumaccount  
        If count = result.Count Then  
            str = String.Format("SubTotal {0} {1}", arrcount, sumaccount)  
            list.Add(str)  
            list.Add("--------------------------------------------------")  
        End If  

        count = count + 1  
    Next  
    File.WriteAllLines("test.txt", list)  

Tested result:

Hope my code could help you.

Best Regards,
Jack