Hello and welcome,
I do not believe you can add data to a LiveObject without changing the DataTable.
However, DataTable rows are similar to dictionaries. This means that on the server you can cast a LiveObject row to a dictionary:
my_dict=dict(my_row)
For multiple rows you will need to loop.
With this approach you can compute whatever you wish, update your dict, and return it to the client. On the client side you would then set data bindings to this dictionary accordingly.
Please see here for more information