Open Power Query/Get and Transform. Click on New Query.
Open blank query in the editor, launch Advanced Editor and paste in the following code.
Assumes your range of data is named Table1
let
Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Week", type text}, {"Country1", Int64.Type}, {"Country2", Int64.Type}, {"Country3", Int64.Type}}),
#"Unpivoted Other Columns" = Table.UnpivotOtherColumns(#"Changed Type", {"Week"}, "Attribute", "Value"),
#"Reordered Columns" = Table.ReorderColumns(#"Unpivoted Other Columns",{"Attribute", "Value", "Week"})
in
#"Reordered Columns"
Bookmarks