E.G. assign column A as inches. Data is imported from measurements I had taken, I put in excel and saved as a .txt file
If it is a display thing, then you set the units of the data frame accordingly...but if it isn't about displaying, then ArcMap could care less. You could have given a field name to allude to the fact ... data_inch
An overview of the Excel toolset—Help | ArcGIS for Desktop
And have you clicked the big add data button and navigated to the file to load it? or are you wanting to create the table in arcmap instead.
I've created the file and already loaded it into ARC MAP, I want to let ARC MAP know that the x value is in inches.
Retrieving data ...