"The menu is over the plate."
अनुवाद:मेन्यू प्लेट के ऊपर है।
They are quite synonymous in meaning, however these examples may help:
"The boy is sitting OVER the chair" is a wrong sentence, the correct sentence will be "... ON the chair". Further you can say (The bird flew OVER my house) not (... ON my house).
you will yourself come to know the difference as you come across more number of sentences.