Excel - How do I make rows that contain row headers into two columns

Question

I have a table with several rows of data in it. The row's header appears in the first cell of the row. While preserving the row heading, I'm attempting to convert the rows into two columns.

Row-containing table In the given instance, there are two. More might be present.

A	B	C	D	E
Row Header 1	12	34	56	78
Row Header 2	90	23	45	67

End Result:

A	B
Row Header 1	12
Row Header 1	34
Row Header 1	56
Row Header 1	78
Row Header 2	90
Row Header 2	23
Row Header 2	45
Row Header 2	67

Answer 1

You can use this formula:

=LET(values,B1:E2,
headers,MAP(values,LAMBDA(v,INDEX(A1:A2,ROW(v)))),
HSTACK(TOCOL(headers),TOCOL(values)))

Via MAP the row headers are written to the same matrix as the values. Then you can use TOCOL to make a single column of each matrix - merging them by HSTACK