Don't know if it's something that people still do today, but I remember those Tupperware parties from when I was a child. Tupperware was developed in 1946 by Earl Silas Tupper in Leominster, Massachusetts.
He developed plastic containers used in households to contain food and keep it airtight. The formerly patented 'burping seal' is a famous aspect of Tupperware, which distinguished it from competitors.
(via Nag on the Lake)