Since you are using workflow, I would approach it the following way:

1. Add a global Assigned Inventory multi-token variable.
2. Add a For Each Row that targets the rows in each of your item tables. Within the for each row, you will add a repeat loop that repeats until quantity is reached. Within your repeat, you will Append the Part name to the multi-value variable we made outside of all the loops.
3. Do the above for each of your tables since you have multiple.
4. Push the multi value token back into the variable used for the Assigned Inventory table at the bottom with the Set variables activity