How to fast insert a JSON into Realm Database for a React Native App

You can do something like:

let objs = JSON.parse('[{"EventID":"3769","EventName":"Birthday Party","EventDate":"Jun 21 2018  4:00 PM"},{"EventID":"4232","EventName":"Homecoming","EventDate":"Jun 22 2018 11:00 PM"}, {"EventID":"3838","EventName":"the Summer Show","EventDate":"Jun 28 2018  2:00 AM"}]');
realm.write(() => {
    objs.forEach(obj => {
        realm.create('Event', obj);
    });
});

You insert all object in one transaction (realm.write()).