Change Column Headers To Names Dynamically Nested in Column_1 by Column Count

Ok, so this works:

let
    Source = Table.FromColumns({Lines.FromBinary(File.Contents("C:\Users\MyComputer\Desktop\Example Log.las"), null, null, 1252)}),
    #"Added Custom" = Table.AddColumn(Source, "curveFinder", each if Text.Contains([Column1], "~CURVE INFORMATION") then "COLUMNS" else if Text.Contains([Column1], "~ASCII DATA AREA") then "DATA" else null),
    #"Filled Down" = Table.FillDown(#"Added Custom",{"curveFinder"}),
    columnNames =
        let
            #"Filtered Rows" = Table.SelectRows(#"Filled Down", each ([curveFinder] = "COLUMNS")),
            #"Removed Top Rows" = Table.Skip(#"Filtered Rows",1),
            #"Removed Bottom Rows" = Table.RemoveLastN(#"Removed Top Rows",1),
            #"Removed Other Columns" = Table.RemoveColumns(#"Removed Bottom Rows",{"curveFinder"}),
            #"Extracted Text After Delimiter" = Table.TransformColumns(#"Removed Other Columns", {{"Column1", each Text.AfterDelimiter(_, " . "), type text}}),
            #"Trimmed Text" = Table.TransformColumns(#"Extracted Text After Delimiter",{{"Column1", Text.Trim, type text}}),
            #"Cleaned Text" = Table.TransformColumns(#"Trimmed Text",{{"Column1", Text.Clean, type text}}),
            #"Replaced Value" = Table.ReplaceValue(#"Cleaned Text"," ","",Replacer.ReplaceText,{"Column1"}),
            Custom1 = #"Replaced Value"[Column1]
        in
            Custom1,
    data =
        let
            #"Filtered Rows" = Table.SelectRows(#"Filled Down", each ([curveFinder] = "DATA")),
            #"Removed Top Rows" = Table.Skip(#"Filtered Rows",1),
            #"Removed Columns" = Table.RemoveColumns(#"Removed Top Rows",{"curveFinder"}),
            #"Split Column by Delimiter" = Table.SplitColumn(#"Removed Columns", "Column1", Splitter.SplitTextByDelimiter(" ", QuoteStyle.Csv), columnNames)
        in
            #"Split Column by Delimiter"
in
    data

I've tested this on your log file, which contains 22 columns. I also incrementally deleted column names and corresponding data columns as part of my tests. It passed those tests.

While this may work now, it is very brittle and makes a TON of assumptions about the structure of your data in the future. Most important assumptions:

1. Column names will always fall under '~CURVE INFORMATION' and the data will always fall under '~ASCII DATA AREA'
2. There will always be a space between the last column name and '~ASCII DATA AREA'
3. Column names will always be after this delimiter: ' . '
4. The data values will always be delimited by a space (' ')

I hope this helps.