if I got that correctly ep_table is the plugin version to go for adding table support; In that case the listetd plugin in UI "ep_datatables" seems to be obsolete and should be removed.
ep_datatables has been removed from npm. It shouldn't be showing up in npm search @isaacs https://encrypted.google.com/search?q=ep_datatables&q=site:npmjs.org&hl=en
The core issue is npm/npm-www#182
But of course, it may still show up in searches (and the command line npm search), since there are a bazillion caches and indexes involved.
@disy-mk Perhaps try npm cache clean <package_name>
npm cache clean <package_name>
Also, this is not really an etherpad-lite issue.