The global action will not work in this case - as it has no connection to a data context. It has no knowledge of the contact rows you have in your table. You will either have to create this fucntionality as a row action (where a single row of the table will be in context and can be used to prepoulate data) or on a mass action, where the action will run sequentially on each of the rows selected - with each row providing context to correctly effect your prepopulation.
I’m still confident you can do this with no code…
However- if you simply want to grab all the rows of the table and add them to the LongList - you could go with a coded solution. Take a look at this tutorial which is not exaclty the same, but has the cues you need: http://help.skuidify.com/m/components/l/109496-mass-create-records
