Hello Ozan,

I will also provide the reply here so it would be available for other users as well.

RadGrid (and other Telerik controls) provides the Mobile RenderMode which is specifically designed for this kind of scenarios and low-res devices. It changes the Menu, Filtering, Sorting, etc. of the grid to suitable match Touch devices:
https://demos.telerik.com/aspnet-ajax/grid/mobile-examples/overview/default.aspx?name=overview&utm_source=AJAX+Demos&utm_medium=QRcode&utm_campaign=Ajax_mobile_demos_qrcode

In addition to that, there is also the Auto RenderMode, which will automatically change the Layout and RenderMode of the grid to Lightweight (Desktop) or Mobile depending on the device:
RadGrid Render Modes

 We also provide various custom solution to our users:

• Example 1: https://www.telerik.com/support/code-library/responsive-radgrid-d82dc6333682
• Example 2: https://www.telerik.com/support/kb/aspnet-ajax/grid/details/stack-responsive-radgrid-columns-on-small-screens

The feature you are asking for seems like a combination between these 2:

1. Multi-Column Headers
2. Cell/Row Merging -  I am afraid this one is not provided automatically by RadGrid. It can be achieved manually similar to the implementation demonstrated in the attached web site sample.
   
   

There are, however, other new features provided by RadGrid:
Grid - Export Multiple Grids

 I understand that you are not so fond of templates, but generally this requirement can be achieved via:

1. RadListView
2. RadGrid DetailItemTemplate
3. A less known way:
   

                 <MasterTableView ...>
                      <ItemTemplate>
                           <telerik:RadLabel ID="RadLabel1" runat="server" Text="Some Content"></telerik:RadLabel>
                 </ItemTemplate>

   
   

The case with all these options is to align the header cells to the item rows, e.g. with custom <table><tr><th/td>, which means additional coding.

I hope this information sheds light upon the matter and clarifies the situation.

Regards,
Eyup
Progress Telerik