is it possible to combine combobox with paging ?
You could use a grid with single selection and place it in an AnimationContainer so it acts like a dropdown.
You can also Follow the implementation of a built-in virtualization feature in this page (I added your Vote on your behalf): https://feedback.telerik.com/blazor/1457808-combobox-virtualization
For the time being, custom filtering through the OnRead event can let you optimize the data queries and number of rendered items: https://docs.telerik.com/blazor-ui/components/combobox/events#onread
In Blazor, what we'd rather do is to have a dropdown grid component, or a dropdown component that lets you put whatever you want in the dropdown (like a grid with paging):
Feel free to Vote for them, and to Follow them for status updates.