i'm in a hotel and i'm confused to do the following :-
1st i have problem that my 10M internet sometimes goes slow when we have 300 Clients ,so i want to put a solution to fix that slow cause by youtube and streaming of cource
2nd i want to add more internet Lines so i can have more two Lines each 16M , so i'll have total in future 10 + 16 + 16 = 42 Mb Internet

1st :
i i'll buy Mikrotik instead the old one i have with more processor ,so i choose this one : RB1100AHx2
so question No. 1 , how can i make mangle for Streaming & Downloading and broswing? any more ideas guys

2nd
i'll need to configure my mikrotik to it can bundle the three lines ,
so Question No. 2 ,is it reliable and how can i do it?

https://www.youtube.com/watch?v=dnLKyu4_md8
This is for 2 WAN but with same config you can use 3 or 4 WAN links!

i'm in a hotel and i'm confused to do the following :-
1st i have problem that my 10M internet sometimes goes slow when we have 300 Clients ,so i want to put a solution to fix that slow cause by youtube and streaming of cource
2nd i want to add more internet Lines so i can have more two Lines each 16M , so i'll have total in future 10 + 16 + 16 = 42 Mb Internet

Your first problem will not be easily addressed. Even if You could block all the big video players (youtube, facebook, redtube, etc, etc, etc), there will always be another one. And 10Mb (did I read it right? Ten megabits?) is quite slow to serve 300 clients. I know, it isn't always easy/cheap to add more bandwidth. I'm just saying that, even for plain sites, this will be slow.

Your second problem is easier to solve. You could, even, use only one of the ports to your internal network, and buy 12 internet lines - one for each remaining port.

1st :
i i'll buy Mikrotik instead the old one i have with more processor ,so i choose this one : RB1100AHx2
so question No. 1 , how can i make mangle for Streaming & Downloading and broswing? any more ideas guys

2nd
i'll need to configure my mikrotik to it can bundle the three lines ,
so Question No. 2 ,is it reliable and how can i do it?

The RB1100AHx2 is a great device. It is stable, fast and quite mature. But it is discontinued. Why not try its successor, the RB1100AHx4? It is the same price range, comes with the same 13 ports, is passive cooled and is quite faster. Its switch is less capable than the RB1100AHx2 - but is mostly about VLANs settings. And with 300 clients I believe You are using some switches anyway.

Question 2: Yes, it is reliable. There is one gotcha: You don't add the link speeds, strictly speaking. No one will be able to do a single download at 10 + 16 + 16 = 42 Mb: they will be able to, at most, download at 16Mb. But You (You = the router) WILL get two downloads at 16MB and one at 10Mb.

I don't have an example here, to help you. There are people here that will be able to help You with this.

https://www.youtube.com/watch?v=dnLKyu4_md8
This is for 2 WAN but with same config you can use 3 or 4 WAN links!

Thanks ,it works with me the 2 WAN put together