The script used in this text is a 3rd century book hand. "Book hand" is a term used to describe the style of writing used primarily for literary texts; book hands tend to be more legible than personal hands (such as are found in documentary papyri) because they are more carefully written and avoid the use of ligatured and cursive forms. Below are examples of all the letters as this scribe wrote them. Take a minute to examine the shapes of the letters—they're probably not that different than how you write upper-case Greek letters.
A few things should be noted. The lunate sigma (which looks like the letter 'c') is the normal form of sigma in most Greek papyri. Greek in this time period made no distinction between upper-case and lower-case (various forms of letters were used over time, and the style known as miniscule was eventually adopted as the lower-case of modern Greek). Thus, in P46 most letters resemble "upper-case" forms, which are typically the older forms of the letters, while some (such as alpha, xi, and omega) are later, more cursive, forms which look more like modern "lower-case" letters.
Most of the letters have roughly the same height, except beta, xi, phi, and psi, which tend to be larger and extend above and below the normal line. This regularity helps make the text easily readable, an important quality for a book hand to have. And while the hand is generally free of ligatures, some letters are crowded to the point of touching one another, but this does not harm the readability of the hand.
You can view this alphabet table at any time while reading the text by clicking on the "view alphabet" link at upper-left of each page.