A network device acting as a forwarding element within a software-defined network receives a representation of configurable flow table definitions and configurable logic for selecting between flow tables. The network device creates a flow table based on each of the configurable flow table definitions and installs the configurable logic for selecting between flow tables. The network device receives data to populate configurable key columns and action columns of the flow tables and populates the flow tables using that data. The network device then selects from forwarding decisions for packets according to the configurable logic for selecting between flow tables, the flow tables, and each packet's values in relevant header fields required by the configurable logic.