procedure TForm1.ADOTable1MemoTGetText(Sender: TField; var Text: String;
  DisplayText: Boolean);
begin
   Text := ADOTable1MemoT.AsString+' Memo';
end;

procedure TForm1.ADOTable1MemoTSetText(Sender: TField; const Text: String);
begin
  ADOTable1MemoT.AsString := Text+ ' test';
end;

  TForm1 = class(TForm)
    DBGrid1: TDBGrid;
    DataSource1: TDataSource;
    Table1: TTable;
    Table1ID: TSmallintField;
    Table1TMemo: TMemoField;
    procedure Table1TMemoGetText(Sender: TField; var Text: String;
      DisplayText: Boolean);
    procedure Table1TMemoSetText(Sender: TField; const Text: String);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Table1TMemoGetText(Sender: TField; var Text: String;
  DisplayText: Boolean);
begin
    Text := Table1TMemo.AsString + ' memo';
end;

procedure TForm1.Table1TMemoSetText(Sender: TField; const Text: String);
begin
    Table1TMemo.AsString := Text + 'text';
end;

function TCustomDBGrid.GetEditText(ACol, ARow: Longint): string;
begin
  Result := '';
  if FDatalink.Active then
  with Columns[RawToDataColumn(ACol)] do
    if Assigned(Field) then
      Result := Field.Text;
  FEditText := Result;
end;

function TField.GetEditText: string;
begin
  Result := '';
  if Assigned(FOnGetText) then
    FOnGetText(Self, Result, False) else
    GetText(Result, False);
end;

procedure TDBMemo.LoadMemo;
begin
  if not FMemoLoaded and Assigned(FDataLink.Field) and
FDataLink.Field.IsBlob then
  begin
    try
      Lines.Text := FDataLink.Field.AsString;
      FMemoLoaded := True;
    except
      { Memo too large }
      on E:EInvalidOperation do
        Lines.Text := Format('(%s)', [E.Message]);
    end;
    EditingChange(Self);
  end;
end;