You can rename a table in modeling mode by clicking on the table name and typing a new name. But it sounds like you are asking for something slightly different than the topic title. I may need some clarification in order to understand what you're trying to solve.
You say you "have some existing dataflows that [you] would like to import from a Xcalar table". Do you mean you'd like to point your batch dataflows to an existing table in a Xcalar modeling session? If so, you can export your Xcalar table to a CSV. Be sure to select "Multiple Files" in the Advanced Options. This will leave you with a folder containing many data files that together, make up the table you exported. Now, parameterize your batch dataflows to point to the folder containing those files.
If this isn't quite what you are asking, please follow up and we can get you the solution you need.
Thanks for the question!