let
  sprData = Excel.CurrentWorkbook(){[ Name = "Сравочник" ]}[Content],
  spr = Table.Buffer ( Table.TransformColumnTypes ( sprData, { { "НачалДата", type date }, { "КонечДата", type date } } ) ),
  lst = List.Buffer ( spr[Процент] ),
  data = Excel.CurrentWorkbook(){[ Name = "Сделки" ]}[Content],
  typed = Table.TransformColumnTypes ( data, { { "Сумма", type number }, { "Дата", type date } } ),
  addPerc = Table.AddColumn (
    typed,
    "Процент",
    ( r ) =>
      try
        lst{Table.PositionOf ( spr, r, Occurrence.First, ( x, y ) => y[Дата] >= x[НачалДата] and y[Дата] <= x[КонечДата] and x[Сделка] = y[Сделка] )}
      otherwise
        null,
    type number
  )
in
  addPerc

let
    Source = Excel.CurrentWorkbook(){[Name="Сравочник"]}[Content],
    #"Added Custom" = Table.AddColumn(Source, "a", each {Number.From([НачалДата])..Number.From([КонечДата])}),
    b = Table.ExpandListColumn(#"Added Custom", "a"),
    Custom1 = Excel.CurrentWorkbook(){[ Name = "Сделки" ]}[Content],
    #"Changed Type" = Table.TransformColumnTypes(Custom1,{{"Дата", Int64.Type}}),
    #"Merged Queries" = Table.NestedJoin(#"Changed Type", {"Сделка", "Дата"}, b, {"Сделка", "a"}, "Changed Type", JoinKind.LeftOuter),
    #"Expanded {0}" = Table.ExpandTableColumn(#"Merged Queries", "Changed Type", {"Процент1", "Процент2", "Процент3", "Процент4"}, {"Процент1", "Процент2", "Процент3", "Процент4"})
in
    #"Expanded {0}"