Hey @mpmohi!
It's possible to restrict the height of your images by setting the Row height to an option other than Dynamic:

Another workaround, albeit a temporary one, might be to use some custom css:
#retool-widget-yourTableId img._5u19W{
max-height: 100px;
}

Finally, you could try using an HTML column which would allow you to define an img element with a style property that limits the maximum height:

The example above uses a URL as the data source, in your case, you could try passing it a data URL instead, something like
<img src="data:img/jpg;base64,{{item}}" style="max-height: 100px" />
Let me know if any of those options work for you!