You can use the AutoPopulateItems property to load the FormatBlock and FontName dropdown boxes either
automatically from the client machine, or from the language XML file under the UltimateEditorInclude\Languages folder.

If the AutoPopulateItems attribute of FormatBlock or FontName in the editor XML file (UltimateEditor.xml by default)
is set to True then the control will automatically load the Paragraph and Font dropdown boxes from the client machine.
Otherwise it loads them from the language XML file (English.xml by default) under the Languages folder.

Note that editor XML file and language XML files are connected over the ID attribute of each ToolbarItem element.

You can also define your own font sizes in language XML file by changing ItemText property as follows:

<ToolbarItem ID="FontSize">
    <DropDown>
        <DropDownItem ItemText="Size" ItemValue="" />
        <DropDownItem ItemText="1 (8 pt)" ItemValue="1" />
        <DropDownItem ItemText="2 (10 pt)" ItemValue="2" />
        <DropDownItem ItemText="3 (12 pt)" ItemValue="3" />
        <DropDownItem ItemText="4 (14.5 pt)" ItemValue="4" />
        <DropDownItem ItemText="5 (18 pt)" ItemValue="5" />
        <DropDownItem ItemText="6 (24 pt)" ItemValue="6" />
        <DropDownItem ItemText="7 (36 pt)" ItemValue="7" />
    </DropDown>
</ToolbarItem>

The only limitation is that you can only define 7 font-sizes and ItemValue has to be an integer from 1 to 7.