Risolto:
codice:
procedure TForm1.Button1Click(Sender: TObject);
Var
    Item: TListItem;
begin
    Item := ListView2.Items.Add;
    Item.Caption := Edit1.Text;
    Item.SubItems.Add(Edit2.Text);
    Item.SubItems.Add(Edit3.Text);
    Edit1.Clear;
    Edit2.Clear;
    Edit3.Clear;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
    if ListView2.ItemIndex >= 0 then
ListView2.DeleteSelected
    else
ShowMessage('Select an item to delete');
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
if ListView2.ItemIndex >= 0 then
begin
Edit1.Text := ListView2.ItemFocused.Caption;
Edit2.Text := ListView2.ItemFocused.SubItems[0];
Edit3.Text := ListView2.ItemFocused.SubItems[1];
end
else
ShowMessage('Could not select any item to load');
end;
Cosi Funziona.