Hello Michael Falconer,
There is no direct way with OpenAccess to combine several queries to one client server call.
If the data is connected like in a Master/Detail view you can use our FetchPlan API to let us load the data in minimal C/S calls.
http://www.telerik.com/help/openaccess-orm/fetchplans.html
If you implement a web or application server you can use our second level cache to keep the data if it is fetched once.
http://www.telerik.com/help/openaccess-orm/2nd-level-cache.html
Sincerely yours,
Jan Blessenohl
the Telerik team