According to https://confluence.atlassian.com/bitbucketserver/markdown-syntax-guide-776639995.html, in order to make a markdown table on Bitbucket it's necessary to use the "|" character, like this for example:

#!Markdown
| Day     | Meal    | Price |
| --------|---------|-------|
| Monday  | pasta   | $6    |
| Tuesday | chicken | $8    |

However, it's not possible to escape the character using a backlash, or any other character for that matter. This means that you basically can't use the Pipe character outside of tables, and you also can't use it as a character on the table itself.