This feature has existed hidden for a long time. I thought I would add it, test it and then if everything was fine, I would tell about it to my users. But... I completely forgot it. So, I remembered about it nearly a year after adding it... Sorry...
It is very easy:
Just write a table within <sortable> tag like this:
<sortable>
Item | Price
--- | ---:
Bread | 3 dollars
Butter | 8 dollars
Milk | 4 dollars
</sortable>
NOTE: between the html tags and the table there must be an empty line. When you write it, you will get a table in the Render mode:
| Item | Price |
|---|---|
| Bread | 3 dollars |
| Butter | 8 dollars |
| Milk | 4 dollars |
If you press on the headers (Item or Price), the table lines will be sorted.