[SalesForce] How to get selected records from list view

Your data tables are sharing virtually all of their bindings and action handlers:

                 onrowaction="{!c.handleRowAction}"
                 selectedRows="{!v.selectedRows}"                                                    
                 maxRowSelection="{!v.maxRowSelection}"
                 onrowselection="{!c.handleSelectedRow}"                                                                 
                 loadMoreOffset="{!v.loadMoreOffset}"
                 sortedBy="{!v.sortedBy}"                                                                
                 sortedDirection="{!v.sortedDirection}"                                                              
                 defaultSortDirection="{!v.defaultSortDirection }"
                 onsort="{!c.handleColumnSorting}"
                 onloadmore="{!c.handleLoadMoreAssets}"

Your controller code doesn't look at which data table is the source of any given event, and instead populates the relevant data into a single component attribute:

    component.set("v.selectedRowsDetails", JSON.stringify(obj) );
    component.set("v.selectedRowsList", event.getParam('selectedRows'));

You will find that this code structure has a number of unexpected effects, including "smearing" of both selection and sorting data across your tables. I would anticipate your infinite loading to behave rather strangely too.

If your tables have data and action that's entirely independent of one another, you'll probably find it easiest to implement separate controller actions for the two tables. You'll certainly need separate attributes to act as backing stores for the table state, such as the sorting order and key and the current selected rows.

you should consider using a change handler instead as pointed out in the documentation:

component.cmp

<aura:component>
    <aura:attribute name="status" type="String" default="open"/>
    <aura:handler name="change" value="{!v.status}" action="{!c.handleChange}"/>
    <lightning:select aura:id="select" name="select" label="Opportunity Status" value="{!v.status}">
        <option value="">choose one...</option>
        <option value="open">Open</option>
        <option value="closed">Closed</option>
        <option value="closedwon">Closed Won</option>
    </lightning:select>
    <lightning:button name="selectChange" label="Change" onclick="{!c.changeSelect}"/>
</aura:component>

controller.js

handleChange: function (cmp, event, helper) {
    //Do something with the change handler
    alert(event.getParam('value'));
}

and for future reference, feel free to refer to the official documentation for examples and component usage. =)