Wendy
To my knowledge there is still no widely accepted syntax for table caption in Markdown. Pandoc uses the following syntax:
| Right | Left | Default | Center |
|------:|:-----|---------|:------:|
| 12 | 12 | 12 | 12 |
| 123 | 123 | 123 | 123 |
| 1 | 1 | 1 | 1 |
: Table caption
MultiMarkdown uses this:
| Right | Left | Default | Center |
|------:|:-----|---------|:------:|
| 12 | 12 | 12 | 12 |
| 123 | 123 | 123 | 123 |
| 1 | 1 | 1 | 1 |
[Table caption]
And other Markdown flavors like GFM have no dedicated syntax at all. I personally would vote for adoption of the Pandoc syntax in JotterPad.