Title: Paste/copy memo's contents
To paste something from the clipboard, use PasteFromClipboard method of control. To copy something to the clipboard use CopyToClipboard.
procedure TForm1.Button2Click(Sender: TObject);
begin
Memo1.SelectAll;
Memo1.CopyToClipboard;
Memo1.Clear;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
Memo2.PasteFromClipboard;
end;