You can use a Directory Tool to read in the file paths of all the spreadsheets you need. Then feed that list into a Dynamic Input Tool which will read them in one at a time and stack them, so long as the fields are all the same in each file.
Or you can use a regular input tool and use a wildcard in the path name to read them all in and stack them, again, so long as the field names/types are all the same.
From there, you can pick the fields you want, and either union them to the master file and then output to the master file by "overwriting" it as an output method. Or you can skip the unioning and just output using the "append to existing sheet" mode.
There a lots of examples of using those tools in the learning path on in the Academy and the free videos.
