I looked at the table that you posted the link too and there is an obvious problem - it shows TOTAL number of violent crimes - not PER CAPITA violent crimes.
If you look at all the countries in the world in descending order by homicide rate per 100,000 people annually you will see that the US comes in at number 108 (of 210). If guns were the cause of violent crime you would expect the US to be number one not number 108.
Almost every single one of the countries that rate higher on this list than the US have very strict gun control. The controlling factor is not the guns - it is the people.