This object reports the total number of EIGRP-derived routes currently existing in the topology table for this autonomous system. This is the live count of everything EIGRP currently knows about for this AS, distinct from just the routes installed in the main routing table, since the topology table also holds feasible successors and other candidate paths not currently active in the RIB. A sudden large jump in this count without a corresponding change in the actual number of routed subnets in the network would suggest something is injecting extra or duplicate topology entries, worth investigating via redistribution configuration.