Problem description & analysis:
In the Excel table below, each row is a product, and the 3rd column is the quantity of the product.

Task: Copy each row N times (N is the cell value of the 3rd column) and display values in the original 3rd column as empty. The expected result is as follows:

Solution:
Use SPL XLL to do this:

=spl("=?.conj(~3 * [~]).run(~3=null)",A2:F9)

As shown in the picture below:

Explanation:
conj()function concatenates members of a sequence. run() function modifies a sequence. “Integer N* a sequence” means copying members of a sequence N times.