Problem description & analysis:

In the following table, column A is the category, and column B includes one or multiple lines of text where the line break is the separator.

The task is to expand each multi-line cell under column B into multiple cells and copy the column A value.

Solution:

Use SPL XLL to do this:

=spl("=?.news@q(~2.import@si();[get(1)(1),~])",A2:B4)

As shown in the picture below:

Explanation:

news@q function generates a new sequence by computing members of an existing sequence; ~2 is the 2ndmember of the current variable; import@si parses a string into a sequence of single-line strings according to the carriage return; get() function returns the loop variable according to the layer number during a multilayer loop.