Using 'nft monitor' solved that: It appears that the extra tables were
added by iptables, which is in Raspbian Buster by default in the package
of the same name:
$ grep -i pretty /etc/os-release
PRETTY_NAME="Raspbian GNU/Linux 10 (buster)"
$ apt-cache policy iptables | head -n 3
iptables:
Installed: 1.8.2-4
Candidate: 1.8.2-4
iptables interferes with nft. Uninstalling it package leaves nftables
alone to create new tables without getting extra, unasked for tables.
$ sudo nft add table ip foobar
$ sudo nft list ruleset
table ip foobar {
}
All set. Thanks.
/Lars
