Check out
101 LINQ Samples[
^] from Microsoft.
Through this you should be able to find the right LINQ phrase.
But perhaps something like this can give you a start?
var groups = from row in rows
group row by row.Column1 into g
select new { GroupKey = g.Key, Value = g };
var results = (from g in groups
order by g.Value.Column2
select g.Value).Take(10);
foreach (var result in results)
{
var name = result.Column2;
}