Can anyone assign btc address with wallet? can anyone assign btc address with wallet? 
I mean if I create like 5 addresses in one wallet, can anyone from outside prove that these 5 addresses belong to one person/wallet?
I know you can see IP that relayed the transaction, but if you use TOR or some other SW there will be plenty of relayed transactions from that IP so it will not say anything.. or am I wrong? Thanks for answers.
Yes it's possible if you don't take care.

Let's imagine you have 1BTC on each of your five BTC addresses.

Now you want to spend 4.5BTC, your transaction will look as following

input:
Addr A (1BTC)
Addr B (1BTC)
Addr C (1BTC)
Addr D (1BTC)
Addr E (1BTC)
output:
Addr X (4.5BTC)
Addr Y (0.5BTC) // the change


By seeing such a transaction you can easily deduce that the Addresses A,B,C,D,E belongs to the same person.

Note that this is not a 100% evidence because several people can put their coins together in one transaction for example for an Assurance contract. 

Note that when you use TOR it creates a static route from your computer to an exit node. If you don't click on the 'Use a new identity' button your transactions will be broadcasted through the same TOR exit node. So click on 'Use a new identity' between each transactions.