procedure TMyForm.MakeChanges;
var
  aBookmark: TBookmark;
begin
  Table1.DisableControls;
  aBookmark := Table.GetBookmark;
  try
    {ваш код}
  finally
    Table1.GotoBookmark(aBookmark);
    Table1.FreeBookmark(aBookmark);
    Table1.EnableControls;
  end;
end;