public class TableDescription : Description 

{
  // Must be called within QueuedTask.Run
  void RenameTableSnippet(Geodatabase geodatabase)
  {
    // Renaming a table from 'Original_Table' to 'Renamed_Table'
    string tableToBeRenamed = "Original_Table";
    string tableRenameAs = "Renamed_Table";

    TableDefinition tableDefinition = geodatabase.GetDefinition<TableDefinition>(tableToBeRenamed);

    SchemaBuilder schemaBuilder = new SchemaBuilder(geodatabase);

    // Table rename 
    schemaBuilder.Rename(new TableDescription(tableDefinition), tableRenameAs);
    schemaBuilder.Build();
  }
}

{
  // Must be called within QueuedTask.Run
  void RemoveFieldTableSnippet(Geodatabase geodatabase)
  {
    // Removing all fields from 'Parcels' table except following 
    // Tax_Code
    // Parcel_Address

    // The table to remove fields
    string tableName = "Parcels";

    TableDefinition tableDefinition = geodatabase.GetDefinition<TableDefinition>(tableName);
    IReadOnlyList<Field> fields = tableDefinition.GetFields();

    // Existing fields from 'Parcels' table
    Field taxCodeField = fields.First(f => f.Name.Equals("Tax_Code"));
    Field parcelAddressField = fields.First(f => f.Name.Equals("Parcel_Address"));

    FieldDescription taxFieldDescription = new FieldDescription(taxCodeField);
    FieldDescription parcelAddressFieldDescription = new FieldDescription(parcelAddressField);

    // Fields to retain in modified table
    List<FieldDescription> fieldsToBeRetained = new List<FieldDescription>()
      {
        taxFieldDescription, parcelAddressFieldDescription
      };

    // New description of the 'Parcels' table with the 'Tax_Code' and 'Parcel_Address' fields
    TableDescription modifiedTableDescription = new TableDescription(tableName, fieldsToBeRetained);

    SchemaBuilder schemaBuilder = new SchemaBuilder(geodatabase);

    // Remove all fields except the 'Tax_Code' and 'Parcel_Address' fields
    schemaBuilder.Modify(modifiedTableDescription);
    schemaBuilder.Build();
  }
}