type
 TForm1 = class(TForm)
  procedure LoadTab(Sender: TObject; const FileName: TFileName);
  procedure OeffnenClick(Sender: TObject);
  procedure SaveTab(Sender: TObject; const FileName: TFileName);
  procedure Speichern1Click(Sender: TObject);

procedure SaveTab(Tab: TStringGrid; const FileName: TFileName);
var
  f:   TextFile;
  i, k: Integer;
begin
  AssignFile(f, FileName);
  Rewrite(f);
  with Tab do
  begin
    // Write number of Columns/Rows
    Writeln(f, ColCount);
    Writeln(f, RowCount);
    // loop through cells
    for i := 0 to ColCount - 1 do
      for k := 0 to RowCount - 1 do
        Writeln(F, Cells[i, k]);
  end;
  CloseFile(F);
end;

procedure TForm1.Speichern1Click(Sender: TObject);
begin
 SaveTab(Tab, 'c:\grid.txt');
end;

procedure LoadTab(Tab: TStringGrid; const FileName: TFileName);
var
  f:         TextFile;
  iTmp, i, k: Integer;
  strTemp:   String;
begin
  AssignFile(f, FileName);

  with Tab do
  begin
    // Get number of columns
    Readln(f, iTmp);
    ColCount := iTmp;
    // Get number of rows
    Readln(f, iTmp);
    RowCount := iTmp;
    // loop through cells & fill in values
    for i := 0 to ColCount - 1 do
      for k := 0 to RowCount - 1 do
      begin
        Readln(f, strTemp);
        Cells[i, k] := strTemp;
      end;
  end;
  CloseFile(f);
end;

procedure TForm1.OeffnenClick(Sender: TObject);
begin
 LoadTab(Tab, 'c:\grid.txt');
end;