Хранение таблицы с данными

Public Class Form1
    Dim dt As DataTable
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        dt = New DataTable
        dt.Columns.Add("Name")
        dt.Columns.Add("Adress")
        DGV1.DataSource = dt
    End Sub
 
End Class

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim tbl As DataTable
        Dim da As New OleDb.OleDbDataAdapter
        Dim cn As New OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source='D:\test.xlsx';Extended Properties=""Excel 8.0;HDR=YES;""")
        cn.Open()
        da.SelectCommand = New OleDb.OleDbCommand("Select * from [Лист1$]", cn)
        tbl = New DataTable
        da.Fill(tbl)
        DataGridView1.DataSource = tbl
    End Sub

Imports System.IO
Public Class Form1
    Dim dt As New DataTable
    Dim ds As New DataSet
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        If IO.File.Exists("C:\Users\админ\Desktop\Новая папка\tabl.xml") = False Then
            dt.Columns.Add("Name")
            dt.Columns.Add("Adress")
            ds.Tables.Add(dt)
            DGV1.DataSource = dt
        Else
            ds.ReadXml("C:\Users\админ\Desktop\Новая папка\tabl.xml")
            DGV1.DataMember = "Test1"
            DGV1.DataSource = dt
        End If
    End Sub
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        For Each r As DataRow In dt.Rows
            MsgBox(r.Item(0).ToString & " " & r.Item(1).ToString)
            dt.TableName = "Test1"
            ds.WriteXml("C:\Users\админ\Desktop\Новая папка\tabl.xml")
        Next
    End Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        dt.TableName = "Test1"
        ds.WriteXml("C:\Users\админ\Desktop\Новая папка\tabl.xml")
    End Sub

DGV1.DataSource = ds