I have an table with datas in confluence RTE, while migrating into XWiki. Table alignment was improper.
Confluence Table
XWiki Table
I have migrated another page with different table structure where migration is fine.
You seems to have ended up with one too many | somewhere in the XWiki syntax result. Might be a xwiki/2.1 bug (not escaping properly a | char in the middle of a table) or a bug in the Confluence parser (but it really looks like a xwiki/2.1 renderer side bug especially since I see a | at the end of your content). Could also be a bit of both since I see your screenshot seems to not be properly converted.
As a workaround if you did not edited this page with the WYSIWYG (if you did you can revert it in the history) what you could do is edit it with wiki editor (if you are not advanced user you can edit the document and put ?editor=wiki in your URL) and see if you have some | right before the code example (there might also be a few new line that should not be there) and try to remove it.
Would also be great if you could create a jira issue with the details to reproduce it (create it on Confluence extension side since that where you found it and I will figure out if it should be moved or not).
9.1.5 module is out.