<TelerikGrid Data="@GridData"
             EditMode="@GridEditMode.Incell"
             SelectedItems="@SelectedItems"
             SelectionMode="GridSelectionMode.Multiple"
             SelectedItemsChanged="@( (IEnumerable<Product> items) => SelectedItemsChanged(items) )">
    <GridColumns>
        <GridCheckboxColumn SelectAll="false" Title="Select" Width="70px" />
        <GridColumn Field=@nameof(Product.Name) Editable="false" Title="Product Name" />
        <GridColumn Field=@nameof(Product.Price) Title="Price" />
    </GridColumns>
</TelerikGrid>

@code {
    List<Product> GridData { get; set; }
    IEnumerable<Product> SelectedItems { get; set; } = new List<Product>();

    async Task SelectedItemsChanged(IEnumerable<Product> items)
    {
        if (items.Any())
        {
            SelectedItems = new List<Product>() { items.Last() };
        }
        else
        {
            SelectedItems = new List<Product>();
        }
    }

    protected override void OnInitialized()
    {
        GridData = new List<Product>();
        var rnd = new Random();

        for (int i = 1; i <= 5; i++)
        {

            GridData.Add(new Product()
            {
                ID = i,
                Name = "Product " + i.ToString(),
                Price = (decimal)rnd.Next(1, 100),
                Quantity = (short)rnd.Next(1, 100)
            });
        }
    }

    public class Product
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public decimal Price { get; set; }
        public short Quantity { get; set; }
    }
}