Runtime sharing of unit memories between match tables in a network forwarding element

A method of sharing unit memories between two match tables in a data plane packet processing pipeline of a physical forwarding element is provided. The method, from a plurality of available unit memories of the packet processing pipeline, allocates a first set of unit memories to the first match table and a second set of unit memories to the second match table. The method determines that the first set of unit memories is filled to a threshold capacity after storing a plurality of entries in the first set of unit memories. The method de-allocates a first unit memory from the second match table by moving contents of the first unit memory to a second unit memory in the second set of unit memories. The method allocates the first unit memory to the first match table.