Combine Rows in Power Query
First, if you want the best video guide on the internet about this, check out this video here. Excel on Fire's youtube channel is amazing, both for the depth of knowledge and the pure fun of his teaching style.
In the Home tab, click "Group By", next to Split Column.
In the Group Box box: select the grouping column in the top left box, your other column in the rightmost box. Hit OK - and you should get an error.
Click "Advanced Editor" in the Home tab, right next to Refresh Preview.
Towards the bottom, find the code "List.Sum" and replace it with "Text.Combine". ALSO, after the last "]" there, add a delimiter between quotes.
Done!
