The question is not totally clear. You have a file generated in Excel that you want to import in R? Then the easiest solution is to export the file from Excel as csv, then load it in R using read.csv() or read_csv() in the readr package.
You can also import an Excel sheet directly with the package readxl for example, but you might run into difficulties depending on how the data is organized inside the Excel sheet.
In both cases things are much, much easier if the Excel sheet only contains a single table.