(question from the web)
Not sure if my Title makes sense, but I'm not sure how else to explain it. I am looking to take the first table (Column A and B) and convert it to return unique values for each unique value in column A. Below is an example and what I am looking the out.

Data I currently have (real data is 50k+ rows)
ABC 123
ABC 123
ABC 456
ABC 789
DEF 123
DEF 123
DEF 789
GHI 1010
GHI 1010

Outcome I am looking to get:
ABC 123 456 789
DEF 123 789
GHI 1010

What is the best approach to do this? I appreciate the help and thank you in advance.
ColA ColB ColA ColB
ABC
123
 ABC 123 456 789
ABC
123
 DEF 123 789
ABC
456
 GHI 1010
ABC
789
DEF
123
DEF
123
DEF
789
GHI
1010
GHI
1010

Code:
let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    Group = Table.Group(Source, {"ColA"}, {{"Count", each _, type table}}),
    List = Table.AddColumn(Group, "ColB", each List.Distinct([Count][ColB])),
    Extract = Table.TransformColumns(List, {"ColB", each Text.Combine(List.Transform(_, Text.From), " "), type text})
in
    Extract