azure-storage-table/src/Table/TableRestProxy.php
public function insertOrMergeEntity(
        $table,
        Entity $entity,
        TableServiceOptions $options = null
    ) {
        return $this->insertOrMergeEntityAsync($table, $entity, $options)->wait();
    }
public function insertOrMergeEntity(
        $table,
        Entity $entity,
        TableServiceOptions $options = null
    ) {
        return $this->insertOrMergeEntityAsync($table, $entity, $options)->wait();
    }
Updates an existing entity or inserts a new entity if it does not exist
in the table.

@param string              $table   name of the table
@param Entity              $entity  table entity
@param TableServiceOptions $options optional parameters

@return UpdateEntityResult

@see http://msdn.microsoft.com/en-us/library/windowsazure/hh452241.aspx