The EAT has published its list of Familiar Cases. These are the cases that are so commonly cited that the EAT keeps copies of them to hand. This means that, if you are referring to one of them, you don’t need to include it in your authorities bundle.
I think this is an excellent idea. Anything that reduces the size and weight of authorities bundles is a good thing.
But there are a couple of potential pitfalls.
First, as I read the EAT’s guidance, there will be sufficient copies for the EAT, but you may need to bring a copy for yourself. [Edit: Nathaniel Caiden of Cloisters tells me that there will be copies for the parties as well. The rest of this post has been lightly edited to reflect this.]
Second, the Familiar Cases Bundle contains the formally reported version of the case where available.
If you don’t have access to those reports before the hearing, this means that the version the EAT uses may be slightly different. And, they will have the headnote summary from the law report, which you will not. This will not normally make any difference (it’s still the same case), but it’s worth knowing so you don’t get thrown. Similarly, if you do have access to the reports, it’s worth making sure use the same version the EAT is using. There is potential for confusion if you are talking about the IRLR version, while they are looking at the AC version.
If you do refer to a case on this list in your appeal or skeleton, I think it is worth pointing out that it is a Familiar Case. For example, you might cite Polkey as Polkey v A.E. Dayton Services Ltd  1 AC 344, HL [Familiar Case 14]. This makes it clear to the EAT where they should be looking for it.