Can a Muslim take his wife and children to a restaurant for entertainment? I am a wife doing a lot of work at home and the children get bored over the weekend. I am dreaming of such a thing. Please advise.

There is nothing wrong with that. However, a Muslim should always stay away from any gathering in which Allah swt is disobeyed, a well as he should do his best eating what is lawful.
 
In your case, if there are some restaurants in your area who do not serve alcohol or have a bar vs. some who do so, then-definitely- you should refrain from going to the ones who serve alcohol.
 
The same rule applied for those who serve meals contain pork products vs. those who do not, since many of them do not care about using the same utensils for the pork and non-pork products, although they should not do so by law!