Or just:
For new items per line:
[highlight=vb.net]
ListView1.Items.AddRange(TextBox1.Lines.Select(Fun ction(line As String) New ListViewItem(line)).ToArray())
[/highlight]
For subitems:
[highlight=vb.net]
Dim lvItem As New ListViewItem(TextBox1.Lines(0))
lvItem.Subitems.AddRange(TextBox1.Lines.Skip(1).Se lect(Function(line as string) new listviewitem.listviewsubitem(lvItem, line)).ToArray())
ListView1.Items.Add(lvItem)
[/highlight]