You can try changing it to this:
If myTableData.Rows.Count > 0 Then
For i As Integer = 0 To myTableData.Rows.Count - 1
''Dim DataType() As String = myTableData.Rows(i).Item(1)
ListBox2.Items.Add(myTableData.Rows(i)(1))
Next
End If
Note: Your loop needs to be one less than the row count since it's a zero-based index.