We can use Schema.getGlobalDescribe() to get all properties of sObject.
Apex Class:

public class SampleController {
    
    Public string selectedObj{get;set;}
    
    Public List<Selectoption> getObjList(){
        List<Schema.SObjectType> objList = Schema.getGlobalDescribe().Values();     
        List<SelectOption> objNames = new List<SelectOption>();
        objNames.add(new SelectOption('','-- Select --'));
        for(Schema.SObjectType obj : objList)
        {
            objNames.add(new SelectOption(obj.getDescribe().getName(),obj.getDescribe().getLabel()));
        }
        objNames.sort();
        return objNames;
    }
}

Visualforce Page:

<apex:page controller="SampleController">
    <apex:form >
        <apex:pageBlock>
            <apex:outputlabel value="Object Name" for="plObj"/>      
            <apex:selectList value="{!selectedObj}" multiselect="false" id="plObj" size="1">
                <apex:selectOptions value="{!ObjList}"/>
            </apex:selectList>
        </apex:pageBlock>
    </apex:form>
</apex:page>

Output: