[SalesForce] Lightning Datatable Not showing the data

I created one Lightning datatable component, its syntactically correct but still not displaying the data.
I have attached here my component's code do let me know if i am missing something or it is a bug.

component:

<aura:attribute name="conlist" type="Contact[]"/>
<aura:attribute name="ContactColumns" type="List"/>

<aura:handler name="init" value="{!this}" action="{!c.doInit}"/>

<lightning:datatable data="{!v.conlist}"
                     columns="{!v.ContactColumns}"
                     Keyfield="Id"/>

controller:

({
    doInit : function(component, event, helper) {

        component.set('v.ContactColumns',[
            {label: 'contact Name', fieldName: 'Name', type: 'text'},
            {label: 'Phone', fieldName: 'Phone', type: 'Phone'},
            {label: 'Email', fieldName: 'Email', type: 'Email'},
        ]);
            helper.getData(component);

            }
})

helper:

({
    getData : function(component) {
        var action = component.get('c.getContacts');
        action.setCallback(this, $A.getCallback( function(response){
            var state = response.getState();
            if(state ==="SUCCESS"){
                component.set('v.conlist',response.getReturnValue());
            }else if(state ==="ERROR"){
                var errors = response.getError();
                console.error(errors);
            }
         }));
        $A.enqueueAction(action);
    }
})

Apex controller:

public class dataTableController {

    @AuraEnabled
    Public static List<Contact> getContacts() {
        List<Contact> contacts = [Select Id, Name, Phone, Email FROM Contact LIMIT 10];
        return contacts;
    }

}