Let’s say your GeoJSON looks like this

Copy it in a location on the same server where you have your PostGIS database installed. Then use ogr2ogr to do the job. 

# NOTE: you don't even need to create your table beforehand
ogr2ogr -f "PostgreSQL" PG:"dbname=your-database-name user=your-username password=mypassword" /path/to/jour/GeoJSon/file -nln table-name