Ideally, Qutub Minardi is just a minor standing in between of some area and there's nothing much around. But I'm sure u can stand next to the minor and look it it for a long time. When u notice each and every detail in the minor, it simply amazes you.
They also have a huge gate like structure and some old wall remains where you can take some cool "selfies" with your kids.
A bright day is ideal for this picnic, but don't plan on a hot day as the entire space is quite open and too much heat will be a problem.
It does involve a small ticket for entering the monument, but it's not much at all.
I'd love to spend a picnic here as there is space for you to play your own games and enjoy with your group as it is not overwhelmingly crowded.
It's a must go for all tourists as well as local Delhi audience, not just for its historic value, but also for the grand amazement it has to offer.