Auto generated fields when creating a table

Hello Guys, I am on the "create a table" video in the introductory series of the course. I am using the provided excel sheet "Tesla Sales Data". There is an auto generated field "number of rows" which automatically pops up on the authors worksheet but I do not have that on mine after exporting the data and opening a new worksheet to continue the lesson. This is preventing me from making further progress as that field is added to the workings and i am stuck.  Is there a way I can add it manually?