These days when so many people carry pagers, phones, laptops, earphones, miniature tv sets, etc. etc. (even portable fax machines!) everywhere they go, consideration for the convenience and comfort of those around you needs to be addressed.
Meal times should be an oasis of enjoyment as well as nourishment in most everyone's hectic schedules. It is very rude when your phone keeps ringing and your conversation is so loud that it infringes on the space and privacy of people occupying tables around you. Or when you are sending or receiving faxes at your table...!!(shudder)
It is acceptable (when you are eating alone) to read a newspaper or book at the table, but it is very rude to accept phone calls and carry on a conversation. If you must receive phone calls while trying to enjoy a meal...it is much more acceptable to get up from the table and go to a private, inconspicuous place to continue your conversation. Laptops, portable tv's and fax machines are a definite no-no!
If you are so busy or important that you can't be away from all your communication toys for 45 minutes, you should have your meal brought to your office and let the rest of the world enjoy their meals in peace!