Unlikely other people, I use a 43 inch monitor in my office. Unlike other people, I use a 43 inch monitor in my office.

Last year, I tried to use a 32 inch monitor, which wasI got for my birthday present. Last year, I tried to use a 32 inch monitor, which I got for my birthday present.

At first, it was stoo big for me, but it was very helpful when I worked atfrom home. At first, it was too big for me, but it was very helpful when I worked from home.

Just a stylistic correction :) The sentence is fine the way you wrote it.

At first, it was stoo big for me, but it was very helpful when I worked at home. At first, it was too big for me, but it was very helpful when I worked at home.

My working system doesn't support dual monitors, soand I couldn't see all my work items using a 27 inch monitor. My work system doesn't support dual monitors, and I couldn't see all my work items using a 27 inch monitor.

My workoperating system doesn't support dual monitors, so I couldn't see all work items usingof my windows on a 27 -inch monitor. My operating system doesn't support dual monitors, so I couldn't see all of my windows on a 27-inch monitor.

This year, I had a chance to get a 43 inch monitor which was a test producttry out a test product, a 43 inch monitor. This year, I had a chance to try out a test product, a 43 inch monitor.

"Try out" instead of "get" here, adds clarity to the idea that this is the first time you are using a 43 inch monitor.

This year, I had athe chance to get a 43 -inch monitor, which was a test product. This year, I had the chance to get a 43-inch monitor, which was a test product.

The size of the monitor is almost double of a 27 inch one. The size of the monitor is almost double of a 27 inch one.

This sentence is fine! But if you wanted to, you could delete "The size of the monitor," and just use the pronoun "it," because you have already established that the topic of your paragraph is the monitor.

The size of theis monitor is almost double the size of a 27 -inch one. This monitor is almost double the size of a 27-inch one.

Moreover, the monitor supports UHD videos, so it is the best choice when I watch videos throughon Netflix, YouTube and so on, etc. Moreover, the monitor supports UHD videos, so it is the best choice when I watch videos on Netflix, YouTube, etc.

"Etc."/"and so on" have the same meaning, so just a stylistic choice! :)

Moreover, ithe monitor supports UHD videos, so it is the best choice when Ifor watching videos throughon Netflix, YouTube and so on. Moreover, it supports UHD videos, so it is the best choice for watching videos on Netflix, YouTube and so on.

I totally recommend using a larger monitor when you work atfrom home. I totally recommend using a larger monitor when you work from home.

I totally recommend whenit if you work at home. I totally recommend it if you work at home.