What does Load Balance mean in TL-R470T+ router?

Question

network hardware

Good afternoon, colleagues.
I was faced with a question, the solution of which I do not know yet - to connect several Internet lines (channels) (currently 3 lines) into one, or sum up, or divide by channels in order to distribute Internet access over 3 channels. Because in our area the channel speed is a maximum of 4 Mbps. We decided to lay three lines of 4 Mbit / s (there is an optical fiber channel, but it’s very, very expensive to lay a line far from us) and combine (summarize or distribute) into one. We are 25 people. I found such a solution for the TP-Link TL-R470T + router, in the description of which there is a Load Balance function. Now my questions are:

1. Did I understand correctly about the Load Balance function?
   
2. Does this router support what I need - to unload Internet access by channels.
   
3. Has anyone come across this issue and how did you resolve the issue?
   
4. Has anyone used this router, and can she solve my question.
   

Thanks everyone for the replies and solutions.