Convert the Map Data Type values returned from the Apex Class to an array to display it on the screen using the Lightning Web Component.

Sample Code:

Apex Controller:

public with sharing class SampleLWCController {

    @AuraEnabled( cacheable = true )
    public static Map < Id, Account > fetchMapData(){
        
        return new Map < Id, Account > (

            [ 
                SELECT Id, Name, Industry
                FROM Account
                LIMIT 5
            ]

        );
        
    }
    
}

Lightning Web Component:

HTML:

<template>      
    <template if:true={mapRecords}>
        <lightning-card>   
            <table class="slds-table slds-table_cell-buffer slds-table_bordered slds-table_col-bordered">
                <thead>
                    <tr>
                        <th>Name</th>
                        <th>Industry</th>
                    </tr>
                </thead>
                <tbody>
                    <template for:each={mapRecords} for:item="rec">
                        <tr key={rec.key}>
                            <td>
                                {rec.value.Name}
                            </td>
                            <td>
                                <div>{rec.value.Industry}</div>
                            </td>
                        </tr>
                    </template>
                </tbody>
            </table>
        </lightning-card>  
    </template>      
</template>

JavaScript:

import { LightningElement, wire } from 'lwc';  
import fetchMapData from '@salesforce/apex/SampleLWCController.fetchMapData';  
 
export default class sampleLightningWebComponent extends LightningElement {  

    mapRecords;
    error;
 
    @wire( fetchMapData )  
    wiredMapData( { error, data } ) {

        if ( data ) {

            for ( let key in data ) {

                let tempRec = { value : data[ key ], key : key };

                if ( this.mapRecords ) {

                    this.mapRecords = [ ...this.mapRecords, tempRec ];
        
                } else {
        
                    this.mapRecords = [ tempRec ];
        
                }

            }

            console.log(
                'Records are ',
                JSON.stringify( this.mapRecords )
            );

            this.error = undefined;

        } else if ( error ) {

            console.log(
                'Error is ',
                JSON.stringify( error )
            );
            this.error = JSON.stringify( error );
            this.records = undefined;

        }

    }  
 
}

js-meta.xml:

<?xml version="1.0" encoding="UTF-8"?>
<LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>57.0</apiVersion>
    <isExposed>true</isExposed>
    <targets>
        <target>lightning__Tab</target>
    </targets>
</LightningComponentBundle>

Output: