These dictionaries look like some system objects from Silverlight as the IManagedPeer class is internal. The big memory they occupy might be caused as we generate all the group headers (group headers are not virtualized) and this creates a lot of visual elements and put them in the visual tree. The slow initial load could have the same source - all the headers are created and placed inside the visual tree when the SchedueView control is render for the first time. We are currently working on the UI virtualization of the group headers, but currently only the appointment items are virtualized.
I tried your scenario with some hard-coded resources and appointments and it looks like it is working pretty fast at my side. I'm attaching the project. Could you please let me know if I'm missing something.
the Telerik team
Explore the entire Telerik portfolio by downloading the Ultimate Collection trial package. Get it now >>