You could prepare short anecdotes on one or more of the following:
• travel stories (e.g. missing planes, terrible hotels)
• the worst presentation you ever did
• the best / worst trade fair or conference you ever attended
• new technologies.
These are good topics because they are neutral and everyone in your group is likely to have something to contribute. If you initiate the conversation, it will help to boost your confidence. An alternative to stories / anecdotes are factoids (i.e. interesting statistics), for example factoids about your country, about your field of business, or about anything you find interesting. It is also helpful to learn something about psychology and communication skills. Socializing is all about relating to people and communicating well with the other attendees.
Learning good communication skills and social skills entails knowing how the human brain receives information, and how we perceive each other.