Power Query help

Good, so you add the category-field to the unpivot others step:

// Table1
let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    #"Filtered Rows2" = Table.SelectRows(Source, each ([Column1] <> null)),
    #"Added Custom" = Table.AddColumn(#"Filtered Rows2", "Week", each if Text.StartsWith([Column1], "Week ") then [Column1] else null),
    #"Filled Down" = Table.FillDown(#"Added Custom",{"Week"}),
    #"Promoted Headers" = Table.PromoteHeaders(#"Filled Down", [PromoteAllScalars=true]),
    #"Unpivoted Other Columns" = Table.UnpivotOtherColumns(#"Promoted Headers", {"Week 1", "Week 1_1", "category"}, "Attribute", "Value"),
    #"Renamed Columns" = Table.RenameColumns(#"Unpivoted Other Columns",{{"Attribute", "Date"}}),
    #"Filtered Rows" = Table.SelectRows(#"Renamed Columns", each not Text.StartsWith([Week 1], "Week ")),
    #"Filtered Rows1" = Table.SelectRows(#"Filtered Rows", each ([Value] <> "")),
    #"Renamed Columns1" = Table.RenameColumns(#"Filtered Rows1",{{"Week 1", "Row"}, {"Week 1_1", "Week"}}),
    #"Changed Type1" = Table.TransformColumnTypes(#"Renamed Columns1",{{"Value", type number}, {"category", type text}})
in
    #"Changed Type1"