I have misplaced my wifi card for my PC when I recently moved home. I am currently USING a Windows 8.1 tablet. I do not have a micro HDMI cable to connect the tablet to the monitor.

1 # Am I able to use my tablet as the wifi connection for my PC?

2# Can I connect the tablet via MICRO USB to USB - which I have the adapte for - to the PC so that my tablet screen appears on the monitor (instead of using a HDMI wire)?

3# My final option, I have an Android phone but the power goes down quick. I believe it has a tethering option so I assume this will work if I use the MICRO USB to USB on my PC. If I do, will this keep the Android phone charging whilst its CONNECTED?

My tablet is LINX8 32bit intel atom1gb

I would have tested these options already however my PC is currently in storage and I only want to go pick it up if I can use it to go online with or use the monitor to display my tablet screen.

Using my tablet is suffice but I have been connecting my full size keyboard to it, and my mouse to my keyboard (which has 3 USB ports) and the power on the tablet doesnt last very long so I usually have around 1 hr of keyboard use, and then over 3 hours to fully charge the tablet.

I am on a budget so I am TRYING to avoid buying any new items. If the above options wont work, what will be the CHEAPEST method - to buy a wireless USB card or to buy a MICRO HDMI cable?

I apologise if I have made this sound confusing, I'm terrible when it comes to reading or writing anything technical so I hope anyone reading this can actually understand me.

RegardsFrom what you have described, you want to connect your PC to the Internet but you have missed placed the external adapter used to connect your desktop computer to the Internet.
A desktop computer or laptop computer running the current version of Microsoft Windows can look to the Internet by using a hotspot on an android or Apple device. Also, there are hotspot software apps available on the Windows store for Windows tablets.
https://www.microsoft.com/en-us/store/p/hotspot/9nblggh08s4q

Some android phones have a built-in hotspots feature as part of the standard android package. You should be able to find it under the settings menu.
Also, both USB and Bluetooth tethering are useful options.
From GOOGLE:
Search Results
Follow these steps to set up Internet tethering:
Connect the phone to a computer or laptop by using the USB cable. ...
Open the Settings app.
Choose More, and then choose Tethering & Mobile Hotspot.
Place a check mark by the USB Tethering item.

Here are some links about how to use USB tethering to establish an Internet connection.
http://www.dummies.com/consumer-electronics/smartphones/droid/how-to-tether-an-internet-connection-with-an-android-phone/
(Dud not mean to call you a dummy.)

https://www.quora.com/How-can-I-use-Android-USB-tethering-in-Windows-7-to-connect-computer-to-Internet-via-phones-data-connection

This video is for Windows 10. (Skip the Ad.)
https://www.youtube.com/watch?v=tyBS3rVTxxU
Hope that helps.