How can you properly use Regular Expression (RegEx) table variables in GTM?

Regular Expression (RegEx) table variables in Google Tag Manager (GTM) are used to map values based on regular expression matching. They take an input value, compare it against a series of regular expressions defined in the table, and return a corresponding output value when a match is found. To properly use a RegEx table variable, first define the input variable. This is the variable whose value will be tested against the regular expressions. Next, create the RegEx table. The table consists of rows, each containing a regular expression and a corresponding output value. When GTM evaluates the RegEx table variable, it iterates through each row, comparing the input value against the regular expression in that row. The regular expressions are evaluated in the order the....