You can do many things, some of which I can think of are the following:
1. After you have given them company info, you can ask them to draw creative mind maps of your organization, have them vote for the best one, and give that individual some souvenir. This will help them retain important info in their minds.
2. The suggestion given above is also good. You can engage a trainer or have a senior manager from within your company conduct a session on what makes a thorough professional, how to assimilate into your organizational culture comfortably, and how to build working relationships, etc. In this session, you can use various team-building games available on the internet.
3. On the last day, if you have provided them all presentations and company info in written form, you can ask them to write two questions (with answers) based on the information given to them on separate pieces of paper, fold and put them in a basket. Ask all of them to stand up, then ask each one of them to pick one from the basket. The facilitator should open and ask that question. When somebody answers correctly, they can sit down; if not, they should remain standing and wait for a second chance. Do this with everyone one by one. You can also give them something for correct answers just for fun. We gave chocolate boxes.
Best,
Mona