Hi Raj.
Because the CMDBf webservice is exclusivly used for CI's and their relationships, you don't need to specify a CI table name for the CI's.
Additionaly, the CMDBf webservice is the SDM specific implementation of a company and tool independent standard CI data exchange interface called CMDBf https://www.dmtf.org/standards/cmdbf. Also from this point of view,it wouldnt make sense to be able to specify a tool dependent table name.
Hope that helps and kind regards
..........Michael