Is there a table or list of tare weights of empty spools of various manufacturers? It would be helpful to me if I knew in advance how much the empty filament spool weighs. 

Not having emptied any spool yet, I can't contribute data points, but has anyone compiled a list of empty weights from various manufacturers and sizes?
Yes, there is a table on Reddit - Empty spool weights for estimating remaining filament which suggests that the norm (in 2015) was between 170 and 330 grams for a 1&nbsp;kg spool, superficially in a bimodal distribution clustered around the high and low points. Presumably these were for 3&nbsp;mm filament, this post dating to before the popularity of 1.75&nbsp;mm...

Manufacturer's have an incentive to reduce the mass of their spools, or even ship without spools, since the shipping cost will eat into their profit margin.