<div class="menuTarget">
    right click this context menu target
</div>

<TelerikContextMenu Data="@MenuItems" Selector=".menuTarget">
    <ItemTemplate>
        @{
            var item = context as ContextMenuItem;

            <div id="@item.CSSId" class="context-menu-item">@item.Text</div>

            <TelerikTooltip TargetSelector="@($"#{item.CSSId}")" ShowOn="@TooltipShowEvent.Hover">
                <Template Context="Context">
                    @item.Details
                </Template>
            </TelerikTooltip>
        }
    </ItemTemplate>
</TelerikContextMenu>

@code {

    List<ContextMenuItem> MenuItems { get; set; }

    protected override void OnInitialized()
    {

        MenuItems = new List<ContextMenuItem>()
    {
            new ContextMenuItem
            {
                CSSId = "item1-selector",
                Text = "Item 1",
                Details = "Details for Item 1"
            },
            new ContextMenuItem
            {
                CSSId = "item2-selector",
                Text = "Item 2",
                Details = "Details for Item 2"
            }
        };

        base.OnInitialized();
    }

    public class ContextMenuItem
    {
        public string CSSId { get; set; }
        public string Text { get; set; }
        public string Details { get; set; }
    }
}

<style>
    .context-menu-item {
        width: 100px;
        padding: 5px 10px;
    }

    .k-in.k-link.k-menu-link {
        padding: 0px;
    }

    .menuTarget {
        width: 100px;
        background: yellow;
        margin: 50px;
    }
</style>