concatenate multiple child records into a single value

I have a query made from 5 tables Events_tbl and activity_tbl. The relationship is one-many. on a monthly basis, I prepare a report for the month events. I want instead of having each traveler's name in one row, I want to be able to group all the travelers in few rows. to be clear, the report now is about 15-20 pages. because one trip may have 8 travelers or more. I want to reduce space andf paper. I want to have the names one after the other example: Trip to Italy Travelers:(John Smith, Steve James, Mark Edward) Right now, it will show like this: Trip to Italy Travelers: John Smith Steve James Mark Edward Can this be done? Thanks