De or het lunchlezing?

The correct Dutch article is:

de lunchlezing

Rule Words ending in -ing: almost always de. See the rule

How to use lunchlezing

the lunchlezingde lunchlezing
this lunchlezingdeze lunchlezing
that lunchlezingdie lunchlezing
our lunchlezingonze lunchlezing
your lunchlezingjouw lunchlezing
every lunchlezingelke lunchlezing
which lunchlezing?welke lunchlezing?
a big lunchlezing / the big lunchlezingeen grote lunchlezing, de grote lunchlezing