Create/append a index column

Muzda 

The question is not clear, please have a look at the UNION function: 
https://docs.microsoft.com/en-us/dax/union-function-dax
https://www.youtube.com/watch?v=P-Pov3Fz_Ig

Thank you so much for the answer. I looked at the links you provide to me , but UNION() claim to have the same number of columns in both joined table. In my case I have a table of 9 columns, I want to append another column with a series of number.Here is example of table to demontrate:

Now I want to apend column called index at the end with series of numbers such as 1,2,3,4,5...
I know GENERATESERIES() can provide this series but then how I can add it to that table so that it become:

Thanks