Description
By default, a Value Attribute Table (VAT) is built for any integer grid if the range of values (maximum minus minimum) in the grid is less than 100,000 or the number of unique values is less than 500.
Solution
If you require that the grid have a VAT, use the Build Raster Attribute Table tool. Note that the size of the VAT will depend on the number of unique values encountered and may be constrained by the available disk space.