If text1.Text = "dir1" Then
    dba = new OleDbDataAdapter("select * from dir1", dbc)
    ' actualizaElse
    dba = new OleDbDataAdapter("select * from dir2", dbc)
End If
' Aca debes poner el codigo que usas para mostrar la tabla
 

SELECT Name FROM MSysObjects WHERE ParentId = (SELECT Id FROM MSysObjects WHERE Name = "Tables")

Dim bdc As OleDbConnection
Dim bdcm As OleDbCommand
Dim bdr As OleDbDataReader
Dim bda As OleDbDataAdapter
Dim ds As DataSet

' Abre la conexion
bdc = New OleDbConnection("provider=microsoft.jet.oledb.4.0;data source=" & txtBase.Text)
bdc.Open()
 
' Consulta para devolver las tablas
bdcm = New OleDbCommand("SELECT Name FROM MSysObjects WHERE ParentId = (SELECT Id FROM MSysObjects WHERE Name = 'Tables')", bdc)
bdr = bdcm.ExecuteReader()
 
 
' Lee las tablas
While bdr.Read()
    ' Se usa el Select Case para saltear las tablas del sistema y solo mostrar las creadas por un usuario
    Select Case bdr("Name").ToString()
        Case "MSysAccessObjects"
        Case "MSysAccessXML"
        Case "MSysACEs"
        Case "MSysObjects"
        Case "MSysQueries"
        Case "MSysRelationships"
        Case Else
            lstTablas.Items.Add(bdr("Name").ToString())
    End Select
End While

' Tiene que haber al menos uno seleccionado, sino tira error
If lstTablas.SelectedItems.Count > 0 Then
    bda = New OleDbDataAdapter("SELECT * FROM " & lstTablas.SelectedItem.ToString(), bdc)
    ds = New DataSet()
    bda.Fill(ds, lstTablas.SelectedItem.ToString())
    dg.DataSource = ds
    dg.DataMember = lstTablas.SelectedItem.ToString()
End If