Adding multiple Percentile columns to each Table in a Table of Tables

Hi Jimmy801 ,

No need to modify the PercentileInclusive function. I added it as it is used in the calculation. It is similar to the Excel's Percentile.Inc function, but in Power Query. 

It only means, given a series of values, find out which value is found at the given percentile - in my case, 80th percentile. Some interpolation is done at the end to arrive at a single percentile e.g. incase a value falls between 2 percentiles. .eg. a value 0.482 is falling between the 80th and 81th percentile, then the value is interpolated between the two and result at 80th Percentile could be 0.5. Here is a link for your information purposes:

https://www.datasciencemadesimple.com/percentile-inc-function-in-excel/ 

As for my issue, i tried using your method to optimize the query further a bit. I am attaching a sample workbook and 2 test csv files to load into the workbook.

Two behaviours observed that i need your immediate advice :

1] One thing i hope you can tell me is  - why an extra Column (Column1) gets appended to the query when loading it first time.

2] If i refresh the Query "Manually" or "via VBA Code", the table always gets selected. I came to know that this should not happen. I have just now repaired my Office to be sure, but still the same. Is there a way to turn off this table selection behaviour in Excel? I am using Excel 2016 Pro 64 bit.

Sample CSV files 

Sample Test workbook 

Hope you can help me with this query issue quickly as it is causing my workbook to corrupt when i run this query with VBA code. I have left simple comments in the workbook.