We have the following challenge :
We need to enable/disable components according to users and groups.
How can we do it ? we are having mainly tables and tabs
You can disable queries by group under Advanced Tab.
If you have to enable/disable permissions, you should consider making each component it's own application and at permissions at that level.
Adding on to @ScottR, you can also use the {{current_user}} object to hide/disable/etc conditionally! That object has the current user’s name and permission groups for you to access. Check it out at the bottom of the left panel 
@victoria something like this?
or I suppose you could also use this to hide the component.
{{current_user.groups != "somegrouphere"}}
@barry I would think you would have to for each component. You may want to rethink your architecture if this becomes unmanageable.
^ exactly! You'd have to apply the logic to each component individually (you can always throw components into a container and then apply the logic to just that container), or just split things up between apps.