Search notes:

Reading the data of an Excel Range with Power Query

The following Power Query code reads the data from the range named dataRange, uses the ranges first row to assign column names (Table.PromoteHeaders), specifies the columns' data types (Table.TranformColumnTypes) and assigns the data to the variable tab:
let
   tab = Table.TransformColumnTypes(
           Table.PromoteHeaders(Excel.CurrentWorkbook(){[Name="dataRange"]}[Content]),
           {
             {"Col A" , type text  },
             {"Col B" , type number},
             {"Col C" , type number}
            }
          )
in
   tab

See also

Power Query M formula language: Get data of a (named) range

Index