Do you mean sending masspay ?

sendmany <fromaccount> '{address:amount,...}' [minconf=1] [comment]

sendmany "" '{"1AMMDszd6Jh2Ga5YMnhCin9TyfNHW23sUY":1.354639002,"1FyzUcort6ev7ReXaYBxPQBTq5PmFiSMN":10.0040671}' 1 "escrow.ms payout #5678"

I have seen peoples sending bulk payments/funds to different wallets in a single transaction.
Whats the easiest way to do that ?

https://blockchain.info/merchant/$guid/sendmany?password=$main_password&second_password=$second_password&recipients=$recipients&shared=$shared&fee=$fee

$main_password Your Main My wallet password
$second_password Your second My Wallet password if double encryption is enabled.
$recipients Is a JSON Object using Bitcoin Addresses as keys and the amounts to send as values (See below).
$from Send from a specific Bitcoin Address (Optional)
$shared "true" or "false" indicating whether the transaction should be sent through a shared wallet. Fees apply. (Optional)
$fee Transaction fee value in satoshi (Must be greater than default fee) (Optional)
$note A public note to include with the transaction (Optional)
{
    "1JzSZFs2DQke2B3S4pBxaNaMzzVZaG4Cqh": 100000000,
    "12Cf6nCcRtKERh9cQm3Z29c9MWvQuFSxvT": 1500000000,
    "1dice6YgEVBf88erBFra9BHf6ZMoyvG88": 200000000
}
The above example would send 1 BTC to 1JzSZFs2DQke2B3S4pBxaNaMzzVZaG4Cqh, 15 BTC to 12Cf6nCcRtKERh9cQm3Z29c9MWvQuFSxvT and 2 BTC to 1dice6YgEVBf88erBFra9BHf6ZMoyvG88 in the same transaction.

I have seen peoples sending bulk payments/funds to different wallets in a single transaction.
Whats the easiest way to do that ?

You mean this button?
   
That'd be too easy!

How can you set the network fee with sendmany or the equivalent Blockchain api, or the Electrum CSV import?

For example i want to make 30 payments in bulk and i want to pay 0.00001 network fee for each payment, is it possible ?