Welcome Ann Marie! I hope you have an awesome trip!
I'm trying to remember what we did with our kids last year. One thing we are doing this year is my 9 year old will be doing a Santas Around the World project. He will be interviewing the CM's in each country about Christmas traditions in their homeland. You could adapt this to any other topic that your kids are interested in as well.
The kids' teachers always like them to take pictures and make a scrapbook when we get home, that uses cataloging, writing and sequencing skills.
My 6 year old DD loves to keep records of everything(she even put a sheet of paper on our bathroom door with instructions to check each time we visit LOL) so I will have her keep a journal of fave moments/worst moments each day.etc.
I think, however, that the most important educational activities come under the heading of relationship/social skills. We work VERY hard with our kids before and during each trip on being patient in frustrating situations, being polite and respectful of others, shrugging off minor inconvieniences and annoyances, being tolerant, etc. It is so hard for children to handle those kinds of situations and those skills will be helpful and important for their entire life. So even if you do nothing else, a trip is educational in that regard.
Our motto during our last trip was "No Grumpies!" whenever someone started getting upset, me included, someone would say that and it would be a reminder to take a minute and reassess.
Good luck and I hope you have a great trip!