It is posibble to Expand memory with SSD?

The Problem

The basic issue is that your RAM is separate to your SSD. They are not the same thing. ZRAM is a RAM based memory block that pretends to be a hard drive. So instead of freeing up RAM, it actually consumes memory and uses it to store data just like a small hard drive or USB memory stick.

For example, if you have 512MB of RAM, and you set aside 64MB of that for ZRAM, then you will only have 448MB of system memory available, and a 64MB virtual RAM Drive.

A Possible Resolution

Your only real option is creating a swap file/partition, and using that in combination with your current RAM. As pa4080 stated in the comments, it is not a great option, as even SSD's are much slower than RAM. More information about Swap can be found in the FAQ

A swap partition or file is space where the operating system can temporarily store data that it can no longer store in RAM, so any stale data can be paged out to swap space, while keeping fresh data in RAM. In theory this should allow you to complete the installation process, albeit at a slower rate than if using physical memory.

The Method

During the installation of Ubuntu, while creating the Partition table for your hard drive, you can add; adjust or remove your swap partition. More information can be found here.

The basic steps when you get to the partition stage of your install:

1. Choose your hard drive
2. Click on the "+" button in the bottom left of the screen
3. Choose the size of your new Swap Partition (general rule of thumb is 1-2x the size of your RAM, I would err on the side of caution and go with about 1024MB to 1536MB)
4. Change the "Use as:" drop down to "swap area"
5. click "Ok"
6. Continue to make the remainder of your partitions such as root and maybe /home.

nb. You don't need to specify a filesystem for swap space like you would have to for your root partition

Final Notes

This will not make much of a difference on a machine with very low specs. 18.04 is quite a heavy distribution, and you may need something lighter such as Lubuntu to be able to make it usable.

If you choose to forge ahead with using a swap partition of swap file, then you may be able to tweak it a little bit after installation by adjusting the "swappiness" in /proc/sys/vm/swappiness

You can do this using the methods outlined here

I hope this helps, and good luck!