This Data Pack is meant to give Mekanism's Atomic Disassembler and Meka-Tool compatibility with the Better Combat mod. If you do not have both of those mods installed, you do not need this Data Pack.
Specifically, the Atomic Disassembler is treated as a Cutlass and the Meka-Tool is treated as a single-handed Mace/Hammer.
If you tend to make new worlds rather often, I recommend using the Paxi mod as you can put all of your Data Packs and Resource Packs into that mod's config folders instead of inside each world's save folder and they will work for every world that mod is used on.