I don't understand why heap size keeps increasing when i place a mongodb database query inside a function in my controller.

here is my router

import { Router } from "express";
import profileController from '../controllers/profileController';

class userRouter {
  public router: Router;

  constructor() {
    this.getRoutes();
  }

  getRoutes() {
    this.router.get("/profile-list", profileController.getProfileList);
  }
}

export default new userRouter().router;

here is my controller

import Profile from "../models/profile";

export class profileController {
  static async getProfileList(req: any, res: any, next: any) {
    try {
      const getList = await Profile.find();
      res.status(200).json({
        status: 200,
        message: "Success",
        data: getList,
      });
    } catch (error) {
      console.log(error);
    }
  }
}

here is my model

import * as mongoose from "mongoose";
import { model } from "mongoose";

const profileSchema = new mongoose.Schema({
  userId: { type: String, required: true },
  name: { type: String,  default: ""},
},
{ timestamps: true }
);

export default model("profile", profileSchema);

Total heap size without getProfileList function => 135 MB

Total heap size after placing getProfileList function => 255 MB (specifically after putting const getList = await Profile.find(); )

Here I inspected the memory and found this in comparison:

TypeObject increased from 3MB to 99MB (array) increased from 26MB to 88MB

Any please please help me understand why does it happen? or is it usual in such case.