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;