CAI processes can be either invoked as an API or event-driven. If event-driven, they get triggered on an event. In your case, the event being arrival of a file in a directory monitored by CAI File Connector. There isn't a way to say that wait for 10 files and then trigger the process.
You may want to evaluate File Listener capabilities in IICS. By the way, File Listener can also trigger a taskflow. Please refer Invoking a taskflow through a connector file listener
Informatica Cloud Product Management