Pete’s got it. No bonus dice for improvised shields, but they allow you to use the training.
The rules also state that a character with 2-fisted fighting training and two weapons may use block and strike (BWG pp442). The weapons Appendix tables on pp 554-555 includes fists, bottles, chairs etc as weapons, so, context allowing, yeah I’d allow it but, as mentioned above sans blocking bonus die. Of course the unarmed dude using any old thing (brick, stick, chair etc) he can find to take on the sword-wielding psychopath may look good on paper, but…
John
I’m just still not convinced a platter is a plausible improvised shield. You can hold a large pot lid like a buckler, but you can’t hold something if you can only grip it on the edges. That’s more like a really odd-shaped weapon. But ultimately it’s about what’s fun.
As long as it has the typical platter handles, sure, without a bit of doubt. (And if you have 3min and a foot of string, you can fit it as a shield.
If it has no handles, it’s still workable, but there should be a chance of hitting the fingers…