pas un mince exploit
exploit or prouesse...... I would check Google translate......
"Petit chien" is how you say "small dog" in French.
You can say "petit" for a male small one and "petite" for a female small one in French.
"Small cat" in French is Un petit chat.
exploit
You would say "petite table" in French.
You say trop petit
Un petit appartement.
The small railway station is "la petite gare" in French.
Petite
I think you mean "no small potatoes" or "no small feat" - in slang "oats" refers to feeling young, frisky, and reckless. "No small potatoes" is money slang, meaning something costs a lot. "No small feat" means that something is a big feat, or a big accomplishment.
"Très petit" is how you say "quite small" in French.