Using bitcoin private key sweeper you can quickly sweep your funds (from multiple private keys) into one central wallet. How can you do that?
Blockchain.info
One method to do this is to use the service called blockchain.info The site is a popular bitcoin wallet and blockchain explorer. The service has millions of users, so if you have a lot of funds you may or may not want to use the service.
bitcoin-sweep-privkey
A new alternative is using a python script called bitcoin-sweep-privkey. This script does not rely on a centralized server and instead relies on running the bitcoin core client. Transactions get pushed to the network through your local bitcoind node, so your transactions (if chosen so) never leave your own infrastructure prior to relaying. We had a look at the source code but didn’t do a full audit, so if you want to use it you may want to do that or wait for a few reviews. You can get it from github and use at your own risk: https://github.com/bitcoin-extras/bitcoin-sweep-privkey
Manually
Yes, you could do all transactions by hand in any bitcoin wallet. That’s not very fast however.