HTML page scrollbar takes into account hidden content

I'm using primefaces dataTable with 'scrollable' attribute. And this table cause outer scroll bar to takes into account hidden content.

How can I avoid this behavior?

DataTable settings:

<p:dataTable id = "userLayerSettingsTable" value="#{userSettingsView.layerSettingsTable}" var="settingLayer" style="margin-top: 10px"
             rendered="#{userSettingsView.layerSettingsTable.size() > 0}"
             emptyMessage="Записей не найдено"
             scrollable="true" scrollHeight="268" tableStyleClass="settings-table" rowIndexVar="numLayer">...