If you use a Swimlane/table node you can put in several labels, to suit your data. This is not simple however. You need to
1./ Right click the table node, then select add label. Enter some text. You can edit it later.
2./ With the label selected go to the Edit menu -> Convert Label to Node. Then you can place the text where you need it.
3./ Select all your text nodes, right click (or Edit menu) and raise them above the background so you can see them.
4./ Select all the text nodes again and align them suitably.
5./ Select them again and group them including the table node so that you can move them as one unit if you need to.
It surely could be easier and I would think that would be useful to many users.