LOT is Polskie Linie LOTnicze (Polish Airlines)

Like KLM, there's a bunch of LMs about - there used to be NLM (National, I think), ALM (Antillean), and there is currently SLM (Surinamese) and VLM (Flemish).

Virgin Atlantic is just an expansion of Richard Branson's brand that started off with Virgin Records in the days of Tubular Bells.

Niki is owned by Niki Lauda (see also 'Lauda'). I'm pretty sure Ryanair and Hapag-Lloyd are just names.

Malév is 'Magyar Legiforgalmi Vallalat', Hungarian National Airline.

Presumably Delta has something to do with the fact it started in Mississippi?

And, as everyone knows, Alitalia is Always Late In Take-off, Always Late In Arrival