Yes for most foods you can ignore the use by dates and continue to keep or eat the food well past the use by dates.
For canned foods and other foods that are sealed up including chips, etc the use by date is just a general guideline and doesn't mean the food has gone bad.
However some foods such as milk, bread etc can begin going bad and going sour and growing mold on them when they get a few weeks or so past the use by date.
The same goes for eggs and other things such as meat.
If you want to keep the meat past the use by date it should be kept frozen and the meat can last for a year or so past the use by date but only a few days in the refrigerator.
The eggs can usually last a week or two past the use by date as long as the eggs have remained refrigerated.
You can freeze the eggs to make them last longer as well but the eggs shell will crack in the freezer so you would need to put the eggs in a bag or other freezer safe container.