How do I append a column from one dataframe to another dataframe in power query?

note
- The num of rows are the same.
note
- (I cannot do this in Python, as that will cause the lose of binary files.)
- (why I do such following ex -- this is just a dummy example)
- (I dont have any id as join column)
- (when I tried to convert that to a List then append, the same happens...)
ambiguity
- for append a column, I mean merge/join in power query terminology. (see eg below)

eg:

given

| Content              | Name           | Extension  | Date accessed       | Date modified       | Date created        | Attributes | Folder Path                                                              |
|----------------------|----------------|------------|---------------------|---------------------|---------------------|------------|--------------------------------------------------------------------------|
| Binary.FromText(...) | .gitignore     | .gitignore | 2023/12/12 21:14:57 | 2023/12/12 15:24:49 | 2023/12/12 15:24:49 | [Record]   | G:\wsp\dataset\COVID-19\csse_covid_19_data\csse_covid_19_daily_reports\  |
| Binary.FromText(...) | 01-01-2021.csv | .csv       | 2023/12/12 22:16:12 | 2023/12/12 15:24:49 | 2023/12/12 15:24:49 | [Record]   | G:\wsp\dataset\COVID-19\csse_covid_19_data\csse_covid_19_daily_reports\  |
| Binary.FromText(...) | 01-01-2022.csv | .csv       | 2023/12/12 22:19:20 | 2023/12/12 15:24:49 | 2023/12/12 15:24:49 | [Record]   | G:\wsp\dataset\COVID-19\csse_covid_19_data\csse_covid_19_daily_reports\  |
| Binary.FromText(...) | 01-01-2023.csv | .csv       | 2023/12/12 22:19:20 | 2023/12/12 15:24:49 | 2023/12/12 15:24:49 | [Record]   | G:\wsp\dataset\COVID-19\csse_covid_19_data\csse_covid_19_daily_reports\  |

expected

| Content              | Name           | Extension  | Date accessed       | Date modified       | Date created        | Attributes | Folder Path                                                              | filterout     |
|----------------------|----------------|------------|---------------------|---------------------|---------------------|------------|--------------------------------------------------------------------------|---------------|
| Binary.FromText(...) | .gitignore     | .gitignore | 2023/12/12 21:14:57 | 2023/12/12 15:24:49 | 2023/12/12 15:24:49 | [Record]   | G:\wsp\dataset\COVID-19\csse_covid_19_data\csse_covid_19_daily_reports\  | AppendedData1 |
| Binary.FromText(...) | 01-01-2021.csv | .csv       | 2023/12/12 22:16:12 | 2023/12/12 15:24:49 | 2023/12/12 15:24:49 | [Record]   | G:\wsp\dataset\COVID-19\csse_covid_19_data\csse_covid_19_daily_reports\  | AppendedData1 |
| Binary.FromText(...) | 01-01-2022.csv | .csv       | 2023/12/12 22:19:20 | 2023/12/12 15:24:49 | 2023/12/12 15:24:49 | [Record]   | G:\wsp\dataset\COVID-19\csse_covid_19_data\csse_covid_19_daily_reports\  | AppendedData1 |
| Binary.FromText(...) | 01-01-2023.csv | .csv       | 2023/12/12 22:19:20 | 2023/12/12 15:24:49 | 2023/12/12 15:24:49 | [Record]   | G:\wsp\dataset\COVID-19\csse_covid_19_data\csse_covid_19_daily_reports\  | AppendedData1 |

attempt fail

let
    Source = Folder.Files("G:\wsp\dataset\COVID-19\csse_covid_19_data\csse_covid_19_daily_reports"),
    Source2 = Folder.Files("G:\wsp\dataset\COVID-19\csse_covid_19_data\csse_covid_19_daily_reports"),
    // #"appendedTable" = Table.AddColumn(Source, "filterout", each [Name]) // now "filterout" each contains a String of name << correct
    #"appendedTable" = Table.AddColumn(Source, "filterout", each Source2[Name]) //  now "filterout" each contains a List of names << wrong
in
    appendedTable

(I dont understand why after the append, each row contains a List?
#"appendedTable" = Table.AddColumn(Source, "filterout", each Source2[Name]) // now "filterout" each contains a List of names << wrong)

Solution

To append column Name from table Source2 to Source

 Append = Table.FromColumns ( Table.ToColumns(Source) & {Source2[Name]},Table.ColumnNames(Source)&{"Name"} )