When dealing with Annotation feature classes, the symbology is stored one of two ways: in a symbol collection or in-line. When storing the symbology in a symbol collection, the symbology, e.g., color, size, and font, is stored in the properties of the feature class. Storing the symbology in-line stores the symbology in the attribute table.
When storing the symbology in-line, the size of the feature class increases dramatically and causes slower redrawing of the feature layer. Using the in-line method is not recommended.
In ArcMap, determine if annotation is set to display using in-line symbology by right-clicking on the annotation feature layer and selecting Open Attribute Table. Examine the SymbolID field. If it reads '-1', then the annotation symbology is stored in-line. If it reads 0 or above them, it is stored in a symbol collection.