According to Wictionary, a Stammtisch is “a table in a beer parlour reserved for a group of regulars taking part in social discussion and beer drinking or a group of people gathering at such a table.”
According to IdeaLab/WikiProject Women talk page, it is “a group of regulars”.
And from that page we also find out that on the German Wikipedia, “de-Wikipedia policies have a kind of castle doctrine that allows you to open a project site in your user namespace and disallow disruptive participants while all other project rules (like: no personal attacks, anonymity etc.) are still in place. This is a transparent way how to create a “protected” room for all kinds of movements inside the Wikimedia movement and for those persons who feel the need for a protected room to empower them.”
So what do these German pages look like?
Portal Women (organizing articles around women and possible female topics):
Wiki Project Women (maintenance lists of missing and new articles about women, articles menaced by deletion requests, etc.)
Examples of “castle” user pages
Women’s Teahouse about gender issues (now adopted by a male collegue; he calls that “a little mistake”)
The project Womenedit
Women’s history (about successes in Wikipedia gender issues and successful, as well as some inactive, female de-Wikipedians).
User subpages like Diderot Club (strongly critizing internal happenings and the Wikipedia/Wikimedia “establishment”)
Even one whole user account, de:Benutzer:Grillenwaage, with its talk page as think-tank about de-Wikipedia policies; moderated by few self-elected “owners”.