empty the table not the problem filling it up is 

well, I received forgot password email, but it sends directly to the mail server without using cron. 

I have set my e-mail notifications schedule to "Immediately" 

sent Friendship request to that profile, a private message, and did some posts and comments on his profile

and I got my email with like 10 minutes delay, but that's up to the mail server, probably there's a que of mails 

See screenshot. I'm sorry but we cannot reproduce what you reported on your website

probably you have visited the site before those activity notifications have been sent

yes most works immediately it when set to 2 days thing it must pile them all up and try do in one go or something 

immediately  is not make a pile up 

well, if you willing to wait for up to 2 days, I can do the testing with this setting: 

Automatically (if you don't show up on the site for 2 days)

turned on

in what file are they made mails for Automatically 
maybe theres a way of step them out and not try do all in one time

I'm sorry I don't understand, what you want to do and say, please elaborate. 

it ok il find the file and see if can change it 

Do you want to set Immediately by default or what? 
as the Automaticaly is set by default in the software. 

no what i am try find in the file that makes the emails
but first il try make 2 crons and see if that fixes it 
as im almost 99% shore thats the problem
cron is overloaded

what do you mean by overloaded?

the plugin controls how many notifications to send, which should be deleted etc. 

public function __construct()    {        parent::__construct();
        $this->service = NOTIFICATIONS_BOL_Service::getInstance();
        $this->addJob('expireUnsubscribe', 60 * 60);        $this->addJob('deleteExpired', 60 * 60);
        $this->addJob('fillSendQueue', 10);    }

this can be find in the cron.php file in activity notifications plugin

cron is overloaded  most times it needs run over 1 minute to do all it has to do 

sometimes 2 minutes 

well, you filled your website with a lot of plugins from store, some has the functionality based on cron jobs to be run, you can check which plugin cron jobs are executed in ow_base_cron_jobs table, I believe there a lot

yes and thats why there should be 2 crons 
one for base and base plugins
one for 3 rd party plugins

that how every other script does it so cron does not get over loaded

skadate have fixed it and made 2 crons 

What are you talking about? Skadate DOES NOT have 2 crons, that is 100% false information

i had to make my plugin work on a skatdate site and i am 100% shore on ow cron i seen 2 cron run php 

from memory one was called light cron run the other was heavy cron run

what is light and heavy cron?

skadate has 2 cron runs

light-cron-run.php

and
heavy-cron-run.php

so in cpanel you would need 2 cron commands