Telerik Web Parts for SharePoint 2010 last build was R1 2023 SP2 and is discontinued since then.
SPRadGrid provides the option of binding to SPLists and Excel files on the client. If you prefer a faster loading time and less features, you might as well take advantage of SPRadGrid's client-side binding functionality by switching it on from the tool part GridSettings panel:
The data which the grid is bound to is retrieved through a custom WCF service. Data provision from SQL Server data tables is not supported with client-side binding and neither are insert/update/delete/grouping operations too. SPRadGrid's client-side data-binding is intended for scenarios where the end user experience focuses on fast data display/filtering and sorting.