Question Could this help me to get a better stable internet?

[mmzf]

Explained:

 

[mmzf]

I have a Tenda f3 (V4.0) router i think this is current latest, using it as main router, a wire coming from my isp directly to the modem, isp have a fiber modem near my house from which a ethernet cable attaches to my router (f3), it requires a username and password to access internet (i tried to connect on Tp-link device as PPPoE but failed i don't know what protocol it is). My internet connection speed is 10Mbps.

The issue i am getting is after connecting 5-10 devices on my internet device i know bandwidth is divided, but why does the web interface take enough time to load? it does not have any link with internet speed.. this means my device slows down on load..? I also have a Tp link TL-WR841N(D) V7 its a old device i know, but used to work good and i think is better than tenda f3 latest still... i was thinking to keep f3 as main router without wifi signals, and connect tplink to it with ethernet and spread wifi from tplink, will this help me to speed up device and divide load or something like that?