I am growing melons in my greenhouse for the first time, only previously
having grown them in pots.

The plants are now about 16 inches tall, growing vigorously, and have
started to flower.

Are they too small? Should I remove the flowers till the plants are a bit
bigger?

When growing in pots I let them do their own thing, as I wasn't expecting
more than a fruit per plant anyway. But this time I would like more
fruits, as they have a whole bed to themselves.

Victoria