Some memory fixes

src/components/DataTable.vue

@@ -1,7 +1,6 @@
 <template>
     <div class="data-table-wrapper">
         <el-table
-            ref="tableRef"
             v-loading="loading"
             :data="paginatedData"
             v-bind="mergedTableProps"

src/views/Charts/components/InstanceActivity.vue

@@ -258,6 +258,10 @@
             resizeObserver.value.disconnect();
             resizeObserver.value = null;
         }
+        if (echartsInstance.value) {
+            echartsInstance.value.dispose();
+            echartsInstance.value = null;
+        }
     });
 
     reloadData = async function () {

src/views/Charts/components/InstanceActivityDetail.vue

@@ -95,6 +95,10 @@
             resizeObserver.value.disconnect();
             resizeObserver.value = null;
         }
+        if (echartsInstance.value) {
+            echartsInstance.value.dispose();
+            echartsInstance.value = null;
+        }
     });
 
     function initResizeObserver() {