procedure TMemoToTMemoField;
begin
  TMemoField.Assign(TMemo.Lines);
end;

procedure TMemoFieldToTMemo;
var
  aBlobStream: TBlobStream;
begin
  aBlobStream := TBlobStream.Create(TMemoField, bmRead);
  TMemo.Lines.LoadFromStream(aBlobStream);
  aBlobStream.Free;
end;