How do I get Path Auto to display one value in the URL structure when node:field has multiple values? Using path auto to create a url structure, I would like the following:

my-content-type/[node:field_restaurant_category]

Note that node:field_restaurant_category can have multiple values, and in my url structure this is unfortunately the case. I have a url now that is my-content-type/t1-t2-t3-t4-tetc

How can I limited the node:field_restaurant_category to be just one and only one term? I honestly don't care which term the module chooses so long as the limitation is in place.

I read earlier that something like node:field_restaurant_category:values:1 should work, or something, but I cannot get any logical configuration of that to work correctly.
For multiple cardinality fields you can use a pattern like [node:field-name:1] (note the use of hyphens instead of underscores). 

This is an example of the tokens available for a field called field_profile_categories with multiple values:



I think in your case the pattern should be:

[node:field-restaurant-category:1]


Although the comments in the token table suggest that deltas start at 0, so you might need to use [node:field-restaurant-category:0] if you want the first item to be used.