When editing a page which has an image with table data in its caption, the table is dropped (only its closing tab is kept). The rest of the caption is dropped as well.
Test edit: https://hu.wikipedia.org/w/index.php?title=Vall%C3%A1s&diff=13696305&oldid=13696296
You don't need to interact with the image in any way for this to happen, just edit the page, change anything and save.
Version: unspecified
Severity: major
URL: https://hu.wikipedia.org/wiki/Vall%C3%A1s?oldid=13696307
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=61064