I know ArcGIS maps does not let you add more data directly to excel files on attribute tables because they are "read only's." However, I am creating a time series map that requires I continuously add data to my attribute table every day to show the continuous change. How can I do this using an excel file? If not with excel, does downloading the data as a geo-file allow you to add data in the attribute table? Only thing I know is that when you add/edit an attribute table it only allows you to add on an additional field. But what if I don't want to create an additional field, but rather add on to the data within a field?