azure-storage-table/src/Table/TableRestProxy.php
public function mergeEntity(
        $table,
        Entity $entity,
        TableServiceOptions $options = null
    ) {
        return $this->mergeEntityAsync($table, $entity, $options)->wait();
    }
public function mergeEntity(
        $table,
        Entity $entity,
        TableServiceOptions $options = null
    ) {
        return $this->mergeEntityAsync($table, $entity, $options)->wait();
    }
Updates an existing entity by updating the entity's properties. This operation
does not replace the existing entity, as the updateEntity operation does.

@param string              $table   The table name.
@param Entity              $entity  The table entity.
@param TableServiceOptions $options The optional parameters.

@return Models\UpdateEntityResult

@see http://msdn.microsoft.com/en-us/library/windowsazure/dd179392.aspx