The PHENIX experiment at the relativistic heavy ion collider (RHIC) has measured transverse energy and charged particle multiplicity at midrapidity in Au + Au collisions at center-of-mass energies √SNN = 19.6, 130, and 200 GeV as a function of centrality. The presented results are compared to measurements from other RHIC experiments and experiments at lower energies. The √SNN dependence of dET/dη and dN ch/dη per pair of participants is consistent with logarithmic scaling for the most central events. The centrality dependence of dE T/dη and dNch/dη is similar at all measured incident energies. At RHIC energies, the ratio of transverse energy per charged particle was found to be independent of centrality and growing slowly with √SNN. A survey of comparisons between the data and available theoretical models is also presented.