Line a large baking sheet with paper towels. Arrange the cucumber slices on the paper towels. Sprinkle the cucumbers with salt. Let sit for about 10 minutes. Use a paper towel to gently pat the cucumbers dry.
Meanwhile, in a medium bowl, stir together the cream cheese and mayonnaise until smooth. Add the fresh herbs, black pepper, and lemon juice. Stir to combine.
Spread a thin layer of the cream cheese mixture on each slice of bread. Evenly layer the cucumber slices over half of the bread slices.
Place the remaining slices of bread on top and gently press down. Trim off the crusts. Cut each sandwich into triangles, squares, or rectangular fingers. Serve immediately.
Notes
This recipe yields 4 full-size sandwiches or about 16 finger sandwiches. You can scale the recipe to make more or less sandwiches depending on the size of your group.
Make Ahead: Prepare the cream cheese spread up to 2 days in advance. Let it sit on the counter and come to room temperature for at least 30-60 minutes before using. Within 4-6 hours of serving, assemble the sandwiches. Cover the sandwiches with a slightly damp paper towel and then wrap tightly with plastic wrap or place in an airtight container. Refrigerate until ready to serve.