The Bump tab is part of the V-Ray Material parameters.
Bump
Bump Map – Allows you to select a texture for the bump or normal map. Leaving this unconnected turns off bump/normal mapping.
Bump Amount – A multiplier for the bump map effect.
Bump Type – Determines how the Map parameter is interpreted.
Bump map – Applies the map as a bump map.
Normal map in tangent space – Applies the map as a normal map in tangent space.
Normal map in object space – Applies the map as a normal map in object space.
Normal map in screen space – Applies the map as a normal map in screen/camera space.
Normal map in world space – Applies the map as a normal map in world space.
From texture bump output – The map is applied as determined by map type itself.
Explicit normal – Applies the map as an explicit normal.