yes - in the reporting section of open tables programming, you can export any reports that you run. The reports range from all guests, to guests that have dined a certain number of times, etc. there is a removable thumb drive on the underside of the opentables terminal, so you save your report to that, remove it and plug it in to your computer. Also, some restaurants have their opentables networked with their office computers, so the transfer is a little easier.
Its really fairly simple, and their opentable consultant should be able to walk them through it if they have any problems.