I am a bit confused, as during my studies I learnt that rasters have only one cell value and for some it might be true, as the attribute table is greyed out in ArcGIS. But for others, multiple fields are provided, so the assumption seems to be wrong.
Can anyone explain me the difference of rasters that can contain one or multiple fields?
In ArcGIS an attribute table can be created for raster, but only for integer raster, not for float raster (see the "Build Raster Attribute Table" function).
Best Answer
The difference you are observing is due to the raster cell type: integer or float. Integer rasters are the only raster type that can have more columns than just the VALUE column. Rasters of type float do not have attribute tables. So if the button is greyed out it will be due to the fact it is a float raster. Just go to the layer properties > source to prove it to yourself.