The title of rows in table cells is set as follows.
var source = new MvxStandardTableViewSource(TableView, "TitleText FullName");
How is a subtitle text set along with the TitleText?
If you are using a standard cell type which has a subtitle, then you can use DetailText - see the property in MvxStandardTableViewCell.cs#L73
e.g.
var source = new MvxStandardTableViewSource(
TableView,
UITableViewCellStyle.Subtitle,
"MyCellId",
"TitleText FullName; DetailText Address");
Obviously the standard cell types are fairly limited in what they can display - for more advanced applications, it's best to switch to custom cell types. There are several articles and videos about how to do this - see http://mvvmcross.wordpress.com