why are lines 123-130 an example of irony?

Are these the lines you mean?

My witless heart finds that enjoyable.

So come, suitors, since your prize seems to be

a woman who throughout Achaean land

has no equal, not in sacred Pylos,

Argos, or Mycenae, not on the mainland,

or in Ithaca itself. But you yourselves

know this. Why should I praise my mother?

So come on. Don't delay this competition

with excuses or use up too much time

yes thoes lines

Odysseus claims they are using too much time while he himself has been gone seven years. That's ten years these suitors have been wasting time in Odysseus's home.