Решение моего вопроса в М-коде
let
Source = Excel.Workbook(File.Contents("C:\path\Need to Pivot.xlsx")),
Sheet1_Sheet = Source{[Item="Sheet1",Kind="Sheet"]}[Data],
notNull = Table.SelectRows(Sheet1_Sheet, each [Column1] <> null),
tables = Table.Split(notNull,8),
transform = List.Transform(tables, each Table.PromoteHeaders(Table.FillDown(Table.Transpose(_),{"Column1"}))),
rename = List.Transform(transform, each Table.RenameColumns(_, {{Table.ColumnNames(_){0},"Date"}, {"SensorName", "Time"}})),
combine = Table.Combine(rename),
types = Table.TransformColumnTypes(combine,{"Time", type time})
in
types