There are multiple solutions to this problem however it seems the Menu going wider is an issue of windows 10 bug.
Here are some of the fixes that you can try.
1. shortcut items : If the Start menu is going more wider you can then remove the shortcut items from the start menu and make it shorter. This may take some manual work but it can done if you remove some of the extended items.
2. removing the widgets :Unpin the tiles that you don't want. Apart from removing the widgets, you can also unpin the tiles that gets added as you use them. So the frequently used programs get pinned there. You can unpin them and save some space.
3. Remove Auto update tiles: There are some of the items in the tiles that gets auto update. You have to disable the live update of such tiles. And this way you can also get rid of those with wider size such as weather, cricket, news etc. Removing these live tiles reduces a lot of
4. Switch to classic menu: You can download the classic shell menu. This menu will turn the start menu into Windows 7 like menu. This is a good option considering the tile interface takes lot of resources.
If your Start menu crashes or have any issues while you make fixes. You may want to repair the start menu. In the process you will clean up the lagging issues after repairing. Run the following command in the powershell to check if there is any issue with Start Menu.
If there is no issue then the best option is to download and install the classic shell.