The Great
Assignment
"Therefore go and make disciples of all nations, baptizing them in
the name of the Father and of the Son and of the Holy Spirit."
-Matthew 28:19
The volunteers should completely immerse themselves in information about the country. Depending on how many volunteers are available, a group of volunteers that are assigned to the same country can divide their studies up, with each person studying a certain subject such as food, clothing, artifacts, musical instruments, tools, or culture.
Then plan the event to educate the rest of the congregation. Each country should have a table on which to lay information and foods from that country, while playing background music from the country. Guests should be encouraged to ask lots of questions about the country to try to stump the "experts". Perhaps even have small token gifts for people who stump the volunteers.
Church members can move from table to table, learning about all the different countries. You could also do this with a progressive dinner, with each house representing the culture and food of different countries for different courses of the meal.