An example would be these bench blocks which not only support a workpiece but also have cutouts specific to firearms to make life easier.
TFB Armorer's Bench: Closer Look – Wheeler AR Maintenance MatThe Firearm Blog
Wheeler Engineering AR Armorer's Bench Block
DIY gunsmiths best friend? The Wheeler universal bench block
Wheeler Engineering AR Armorer's Bench Block
At the Armorers Bench: The Not So Universal Bench Block - The Mag Life
AR 15 Armorer's Bench Block
AR 15 Armorer's Bench Block
TFB Armorer's Bench: Closer Look – Ballistic Precision Chronograph Kit - Survival Magazine & News - Bushcraft Prepper Offgrid SHTF Blog & Conservative News
TFB Armorer's Bench: Closer Look – Precision Micro Screwdriver SetThe Firearm Blog
TFB Armorer's Bench: Closer Look– Strike Industries Adjustable Gas BlockThe Firearm Blog
Video – Page 5 – The Armourers Bench
DIY gunsmiths best friend? The Wheeler universal bench block
Guns – The Armourers Bench
TFB Armorer's Bench: Closer Look - Wheeler Bench BlocksThe Firearm Blog
Guns – The Armourers Bench