A set of technologies in .NET for building web applications and web services. Miscellaneous topics that do not fit into specific categories.
The whole point of EF and dbset is to produce a strongly typed entries for tables and query responses.
C# lacks true dynamic objects support, so if you need dynamic queries use ado datatables or use a dynamic language like JavaScript or python.
note: the expando object support you asked about in your previous question is part of the .net dynamic runtime created to support iron ruby and iron python. Microsoft dropped both these products and the dynamic runtime is basically a second class library.