BookStack/resources/assets/sass/_tables.scss

table.table {
  width: 100%;
  tr {
    border-bottom: 1px solid #DDD;
  }
  th, td {
    text-align: left;
    border: none;
    padding: $-xs $-xs;
    vertical-align: middle;
  }
  th {
    font-weight: bold;
  }
  tr:hover {
    background-color: #EEE;
  }
}

table {
  max-width: 100%;
}