Sodium salts have more uses than the metal itself, a crude search in the bibliographic database of the European Patent Office with ‘sodium’ in the title gives 48917 results (as of Friday 8th February 2019).
Sodium metal is used as a heat exchanger in some nuclear reactors, such as illustrated in this 1968 patent entitled ‘Minimizing the positive sodium void coefficient in liquid metal-cooled fast reactor systems’.
The most common compound of sodium is sodium chloride (common salt). It is added to food and used to de-ice roads in winter. It is also used as a feedstock for the chemical industry.
Sodium carbonate (washing soda) is also a useful sodium salt. It is used as a water softener.
Sodium is an extremely reactive metal and the ‘throw a lump of sodium into a beaker of water’-experiment is a favourite at school; those, who missed out may watch this online video.