let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    Source2 = Excel.CurrentWorkbook(){[Name="Table2"]}[Content],
    MQ = Table.NestedJoin(Source, {"Column1"}, Source2, {"Column1"}, "Table2", JoinKind.RightAnti),
    #"Expanded Table2" = Table.ExpandTableColumn(MQ, "Table2", {"Column1"}, {"Column1.1"}),
    #"Removed Columns" = Table.RemoveColumns(#"Expanded Table2",{"Column1"})

in
    #"Removed Columns"