A routing table is a key database in every switching node of a communication network, such as packet switches. For every destination, an entry in the routing table indicates where to send the traffic from that node which is headed to the given destination.
The routing table is usually set up by a routing protocol, and in addition to the data used to handle traffic (e.g. packet forwarding), routing table entries usually also include data used by the routing protocol to do its job, e.g. detecting and preventing routing loops.