We didn't do excursions but here is what was on our bill our first
Disney cruise:
1. Gift shop purchases.
2. Special kids drinks in souvenier cups with the glowing tinkerbell/toy story characters. (They carry these around during the shows like at a ball game. If you have small kids they will be wanting these BADLY!) and they are pretty obvious because they glow. I think ours had milkshakes.
3. A couple drinks of the day.
4. Our tips
5. $40 in laundry (we brought aboard a 3 month old and our 3 year old got a bit of sea sickness so we did a lot of laundry).
6. Cove Coffee (6 days 3 drinks/day). My mom, wife, and myself each had a special coffee each day.
7. M&M's from the theater. (These showed up really strange on our bill. I don't remember how they showed up but I couldn't figure it out. Even when I asked Guest Services they didn't know. I eventually figured it out.)
8. Palo brunch and Palo Dinner
9. Tips from someone else's room. We payed our bill and settled expenses the day before we left so we wouldn't have to wait in line. Imagine my surprise when I looked at the stateroom account the day we were to disembark and saw that our tips went WAY up. I went to guest services and asked what happened and they treated us like we made the mistake on our form. Turns out someone the night before had put their name on their form but our stateroom number so Disney added their tips to our room. It was a huge pain and we had to wait for 40 minutes for them to go through all the forms before they would remove the charge from our bill.
We didn't do any excursions.