Combine Multiple Input Boxes Into One Field

Hey all,
I'm wondering if creating something like this is too difficult, or where I'd start? (see image attached). Here's kind of the process:
Scenario 1 :
1) user selects value from combobox
2) clicks text link ("add") to add value to table
3) value is displayed on form, with "remove" link that can take previously written data out of table
4) combo refreshes, moves down and process can repeat

The values would be added to the table seperated by commas.

Scenario 2:
This might be too difficult, in which case I could just use four or so text inputs and the user could type in the values... all written to different table cells. In this case, I'd need to show be able to write all the cells to a single textbox string on a form in the format "cast member 1, cast member 2" etc.

Anyone know what I'm trying to do and that could lend some advice? If there's an easier way to do this, please let me know. haha, thank yoU!