Description
The attribute table cannot be deleted from the raster dataset, mosaic dataset, or image service when the raster attribute table is stored within the raster format itself, such as .img files.
Solution
Raster dataset—Check to make sure it has .vat.dbf along with the raster data file.
Mosaic dataset—Remove the Attribute Table Function from your function chain.
Image service—These are read-only services; therefore, you cannot remove any attribute tables.