This tool is similar to some experiences at mindfulness retreats (tool 4.3), and you can turn it into a meditation, but that’s not necessary.  Basically, it’s simple: you and another person (or persons) agree to be silent for a particular amount of time. You can choose to partake in activities together or do different activities in the same room simultaneously. The extreme of this is mindful dinners where large groups of people come together to enjoy a meal in total silence.