LINQ to ENTITY select query execution takes long time - WPF

I have a usercontrol in WPF project which it execute a select query which takes a long time this is the code

Entities1 context = new Entities1();                        
 ObservableCollection<E> _E = new ObservableCollection<E>();
CollectionViewSource ECollection = new CollectionViewSource();
ECollection = (CollectionViewSource)this.Resources["EResource"];
 this._E = new ObservableCollection<E>
            (from e in context.Es
             join eg in context.EQ_Gs on e.EQ_G_ID equals eg.EQ_G_ID
             join u in context.Us on e.U_ID equals u.U_ID
             join b in context.Bs on e.B_ID equals b.B_ID
             select e);           
            ECollection.Source = this._E;
            this.Grid_E.ItemsSource = this._E;
            this.Grid_E.DataContext = this._E;
            this.DataContext = ECollection; 
  

and table E has 30000 record it takes aound 2.5 min to load the usercontrol

Thanks Jeff Mercado

I changed the query and used eager loading query it helped a lot and reduced loading time.

var query = context.E.include("B").tostring()