Number of rows is set by the number of channels in the xlobby.xml file
<xmltvChannels>10</xmltvChannels>
<xmltvHours>2</xmltvHours>
I'm not aware of how to change the column width of the channels. Maybe changing the font size
This article covers some epg customizations
http://www.xlobby.com/forum/viewtopic.php?t=1951