Make Bulk Insert Form (PHP + MySQL)

Hi. I have a new script/feature that's awesome. It allows you to generate a lot of rows instantly and enter data into fields then insert them into a table. I need help modifying it to work for another table with some different fields. I need to know how long this will take also. Some of the settings allow you to set a value which pre fills all the new/black insert rows so it's fast to insert data. Some of the data will need this setting and the rest will be filled in manually. This is for restaurant menus and the data is really easy to understand. Item ID, Category ID, Item Name, Item Description, is_active, Locations available at, etc. Item ID is a 24 character alpha numeric that needs to be generated randomly on insert or on row creation. Categories will be created before and it would be nice to have a drop down on each row to quickly assign menu items to Categories, but if that's too difficult then we can simply let the User insert items for a particular Category and set the Category at the top right before we create X insert rows. So for example let's say I need to create 20 new Menu Items for Burgers. Then I can set the Burger Category, enter 20 (for rows to create) then create my blank insert rows. It would also be great to either insert these to a holding table or use session data (ie variables) to prevent the User from losing data while they're filling out all their items. This will help us allow people to upload their Restaurant Menus fast to a system we have. Thanks!!