Tools in the Generalization toolset can be used to aggregate or eliminate features.
Additional generalization tools can be found in the Generalization toolset of the Cartography toolbox.
Aggregates features based on specified attributes.
Eliminates polygons by merging them with neighboring polygons that have the largest area or the longest shared border. Eliminate is often used to remove small sliver polygons that are the result of overlay operations, such as those performed by Intersect and Union tools.
Creates a new output feature class containing the features from the input polygons with some parts or holes of a specified size deleted.