Steps to replicate the issue:

Use the following wikitext:

;Term
:{|
|description
|}

What happens?:

The parser outputs the following HTML with 2 <dl> elements:

<dl><dt>Term</dt></dl>
<dl><dd><table>
<tbody><tr>
<td>description
</td></tr></tbody></table></dd></dl>

What should have happened instead?:

The parser should output both <dt> and <dd> in the same <dl> element:

<dl><dt>Term</dt>
<dd><table>
<tbody><tr>
<td>description
</td></tr></tbody></table></dd></dl>

Other information:

Note Parsoid well handles the code (T262943).

Similar issue: T8776: indented embedded table leaves an unclosed DL, causing unwanted indentation