OOPed everything a little more and added some comments.

connect_gui.py

@@ -1,4 +1,4 @@
 #!/usr/bin/python3
 
 def connect_gui(app):
-    app.main_window.openFile.triggered.connect(app.utils.open_file)
+    app.main_window.openFile.triggered.connect(app.file_actions.open_files)

file.py

@@ -0,0 +1,45 @@
+#!/usr/bin/python3
+
+from PyQt6.QtWidgets import QWidget, QLabel, QFileDialog
+
+
+class FileActions:
+    def __init__(self, app):
+        self.app = app
+
+    def open_files(self):
+        dialog = QFileDialog(self.app.QTMainWindow)
+        dialog.setDirectory(self.app.utils.home_path)
+        dialog.setFileMode(QFileDialog.FileMode.ExistingFiles)
+        dialog.setNameFilters(["Binary (*.bin)", "Any (*)"])
+        dialog.setViewMode(QFileDialog.ViewMode.List)
+
+        if dialog.exec():
+            for file_path in dialog.selectedFiles():
+                self.app.open_files.append(File(self.app, file_path, file_path.split("/")[-1]))
+
+
+class File:
+    def __init__(self, app, path, name):
+        self.app = app
+
+        self.path = path
+        self.name = name
+
+        file = open(path, "r")
+        file_content = file.read()
+        file.close()
+
+        self.content = file_content
+
+        # the widget that contains all the file content
+        self.content_widget = QWidget(self.app.main_window.openFileTabs)
+        self.content_label = QLabel(self.content_widget)  # the label for the text in the file
+        self.content_label.setText(file_content)
+
+        self.app.main_window.openFileTabs.addTab(  # add a tab for the file in the top files list
+            self.content_widget,
+            self.name
+        )
+
+

main.py

@@ -1,45 +1,29 @@
 #!/usr/bin/python3
 
 import sys
-from PyQt6 import QtWidgets
+from PyQt6.QtWidgets import QApplication, QMainWindow
-from gui.main_window import Ui_MainWindow
 from utils import Utils
+from file import FileActions
 from connect_gui import connect_gui
+from gui.main_window import Ui_MainWindow
 
 
 class BreadEditor:
     def __init__(self):
         self.utils = Utils(self)
-        self.open_files = {}
+        self.file_actions = FileActions(self)
 
-        self.qt_app = QtWidgets.QApplication(sys.argv)
+        self.open_files = []
 
-        self.QTMainWindow = QtWidgets.QMainWindow()
+        self.qt_app = QApplication(sys.argv)
+
+        self.QTMainWindow = QMainWindow()
 
         self.main_window = Ui_MainWindow()
         self.main_window.setupUi(self.QTMainWindow)
 
         connect_gui(self)
 
-    def open_file(self, file_path):
-        file = open(file_path, "r")
-        file_content = file.read()
-        file.close()
-
-        self.open_files[file_path] = {
-            "name": file_path.split("/")[-1],  # set name that shows in the tab list
-            "content": file_content
-        }
-
-        content_widget = QtWidgets.QWidget(self.main_window.openFileTabs)
-        content_label = QtWidgets.QLabel(content_widget)
-        content_label.setText(file_content)
-
-        self.main_window.openFileTabs.addTab(
-            content_widget,
-            self.open_files[file_path]["name"]
-        )
-
     def run(self):
         self.QTMainWindow.show()
         sys.exit(self.qt_app.exec())

utils.py

@@ -2,6 +2,7 @@
 
 from pathlib import Path
 from PyQt6.QtWidgets import QFileDialog
+from file import File
 
 
 class Utils:
@@ -9,14 +10,3 @@ class Utils:
         self.app = app
 
         self.home_path = str(Path.home())
-
-    def open_file(self):
-        dialog = QFileDialog(self.app.QTMainWindow)
-        dialog.setDirectory(self.home_path)
-        dialog.setFileMode(QFileDialog.FileMode.ExistingFiles)
-        dialog.setNameFilters(["Binary (*.bin)", "Any (*)"])
-        dialog.setViewMode(QFileDialog.ViewMode.List)
-
-        if dialog.exec():
-            for file_path in dialog.selectedFiles():
-                self.app.open_file(file_path)