  We discuss coexistence of Kondo and spin excitation signals in tunneling
spectroscopy in strongly correlated polyradical $\pi$-magnetic nanographenes on
a metal surface. The Kondo signal is rationalized by a multi-orbital Kondo
screening of the unpaired electrons. The fundamental processes are spin-flips
of antiferromagnetic (AFM) order involving charged molecular multiplets. We
introduce a~perturbative model, which provides simple rules to identify the
presence of AFM channels responsible for Kondo screening. The Kondo regime is
confirmed by numerical renormalization group calculations. This framework can
be applied to similar strongly correlated open-shell systems.
