public class FooAsyncTask implements RT_IAsyncTask {
    public void execute(AsyncRequest__c asyncRequest, Map<String, Object> params) {
        System.debug(params.get('i'));
    }
}

List<AsyncRequest__c> reqs = new List<AsyncRequest__c>();
for (Integer i = 0; i < 50; i++) {
    Map<String, Object> params = new Map<String, Object> {'i' => i};
    reqs.add(RT_AsyncRequestService.create(FooAsyncTask.class, params));
}
insert reqs;