Those inserts could be worth $2 - $10 each new. If they are tungsten
carbide with tantalum carbide in it they are worth about $5 per pound
as scrap maybe more. You can call Emily here and she will tell you.
(These are estimates but I am pretty comfortable with them.)

Solid Tantalum carbide would be a bit unusual. Tungsten carbide with
Tantalum carbide in it would be much more common. My guess is that
the supplier used tantalum carbide much as some use 'vitamin
enriched" on orange juice. It is still mostly orange juice.

The Cemented Carbide Producers Association ( ccpa.org ) has many
publications explaining how things are named, etc. It is a very slow
web site.

Personally I have Kennametal lathe and milling tooling catalogs that I
find very handy for this.

Carbide shapes go in and out of fashion but yours are probably still
good. Before you grind them you might want to consider using them as
is. They may have been meant to be used as wear parts as well. I
agree with Ken Davey but it takes a high skill level to grind them or a
great deal of patience to use a hand file.

tom