I hope that we can preview the table, picture and math in the editor, it will be easier and more useful for us. XD.
Can you please give a small example? A conceptualized figure is preferred.
When the mouse hovers over the figure name:Fig_Q0.png, a preview will show. (This function allows me to check whether the file name is written correctly )

XD
The function in my capture is realized in sublime text by package 'LatexTool'
Unfortunately this seems not possible with the current vscode api. I'll leave this issue open as a feature request.
To at least solve the "check if written correctly" part of this, I think some 'insert relative path' functionality would also be enough.
Similar to this plugin: https://github.com/jakob101/RelativePath
What should be supported I think:
%!tex root = ../Main.tex). Then the correct relative path is ./img/Cat.jpg and not ../img/Cat.jpg.I thought about adding something along these lines back when I added the tex root creation command, as I think these functionalities are related.
What is already here:
In the TexMagician class somwhere is a function that calculates the relative paths of two file paths provided. So the path would be calculated by:
Problems: I don't know if and how people use tex root. Is it for example common, to include some tex file in two different main documents which are in seperate folders? Is it possible to nest tex-root commands?
This one is unlikely, since you never know how many directories are there in a project's root, or how deep they are. Suppose some random guy somehow has his node_modules in the same folder. That is a performance hit.
https://github.com/siegebell/vsc-prettify-symbols-mode has support for real time math prettify in LaTeX.
does not support table and image (I doubt previewing image is possible in vscode version 1.23).
However, this feature does not cover all the math symbol, and it is not in the latest release (v0.4.0) of the plugin. You have to install it yourself.
On this idea, I thought it would be worth linking to an extension that implemented something that seems similar - gutter preview.

@tamuratak do you think you can add support for hovering over images? that would close this issue
I suggest to open a new issue for image preview if there is any interest in this feature.
Most helpful comment
https://github.com/siegebell/vsc-prettify-symbols-mode has support for real time math prettify in LaTeX.
does not support table and image (I doubt previewing image is possible in vscode version 1.23).
However, this feature does not cover all the math symbol, and it is not in the latest release (v0.4.0) of the plugin. You have to install it yourself.