Import Multiple JSON files from folder in PowerQuery

Hello, 

I'm trying to dynamically import .json files as they are placed in a folder within an excel in order to track metrics. I can import a singular file just fine, format it and then add an additional column which generates a timestamp.

However, when I try to replicate this with a folder of .json files, the new files just add columns instead of rows?

What I want is for new files to be appended onto the bottom of the table like this: -

Any ideas how I could achieve this? If it helps my .json file is formatted like this: -

{"accountNumber":"76329873","category1":"redp","q1":"yes","q2":"no","q3":"yes","q4":"yes","q5":"yes"}

{"header":"value","header":value"}