Automator workflow to TAR multiple files in a single directory into multiple TAR archives, in succession?

Aren't you using Automator's "Run Shell Script" with "pass input as arguments"? It produces a skeleton that looks like:

for f in "$@"

do

echo "$f"

done

So you can select multiple folders or files in the finder and have it operate on each object one by one (in place of the echo).

I do a similar thing when I create automator scripts as a Service not Workflow. Then I can select multiple items in the finder and have my script operate on them one by one via the finder's contextual menu.

I don't think I have the following totally fleshed out but you probably can extrapolate on it. This is a service which you can right click a set of folders and it will tar the files within those selected folders with then file names "name xxx.tar", where name is the tar'ed file/folder and xxx is a count within the folder.

I think that is what you originally specified so I am a bit confused by your script with the bit about Archive.tar.

Anyway here the basic idea:

I ran the script directly with a folder argument just to see it indeed tar's up all the stuff inside, one tar per item.

Does it have have to be a tar archived file? what about zip?

If you don't mind using zip, the following workflow works very easily.

This will process each file incrementally. I created it as a service.