Learn Hardcore Hebrew: המפה בתוך הארנק, והטלפון בין הספרים על השולחן. - The map is inside the wallet, and the phone is between the books on the table.

In present-tense Hebrew, is/are is usually omitted. So המפה בתוך הארנק literally looks like the map inside the wallet, but it means the map is inside the wallet. This is completely normal in Hebrew. In past or future sentences, Hebrew does use forms of to be.

What does the prefix ה־ mean in words like המפה, הארנק, הספרים, and השולחן?

ה־ is the Hebrew definite article, meaning the. Unlike English, it is attached directly to the noun:

מפה = a map / map
המפה = the map
ספרים = books
הספרים = the books

So this sentence uses definite nouns throughout.

Why is והטלפון written as one word?

Because ו־ means and, and in Hebrew it usually attaches directly to the following word. So:

ו + הטלפון → והטלפון

This is very common. You should think of ו־ as a short prefix rather than a separate word in most cases.