Right, I stand corrected, wrongfully assumed it was meat.
But as taxy has said, the acidic/sugar value which makes canning jams/jellies/pickles is not really present in a mushroom pate.
shane, you also were asking about single lids, etc. If it is for this pate, my answer pretty much stays the same. Your pate should be good in the fridge for quite some time.
I can only suggest not to make more than you can consume in a reasonable time frame.
Meddle not in the affairs of dragons for you are crunchy and taste good with ketchup.