HTML Javascript Dynamic table for configuring a job using data from MYSQL tables

I want to add some kind of configurator to my existing order form. The customer can select options from a series of interdependent drop-down menus (Data from MySQL). Adding new rows must be possible. The result of this table should be stored as .json on the server. The existing settings area has to be extended so that the 4 tables can be edited completely by an administrator without the use of phpmyadmin.